U.S. patent application number 17/536587 was filed with the patent office on 2022-03-17 for real-time scalable virtual session and network analytics.
This patent application is currently assigned to Citrix Systems, Inc.. The applicant listed for this patent is Citrix Systems, Inc.. Invention is credited to Kirankumar Alluvada, Corneliu Chetan, Jong Kann, Jayadev Marulappa Niranjanmurthy, Georgy Momchilov, Kupuswamy Ramamurthy.
Application Number | 20220086063 17/536587 |
Document ID | / |
Family ID | |
Filed Date | 2022-03-17 |
United States Patent
Application |
20220086063 |
Kind Code |
A1 |
Momchilov; Georgy ; et
al. |
March 17, 2022 |
REAL-TIME SCALABLE VIRTUAL SESSION AND NETWORK ANALYTICS
Abstract
Provided herein are systems and methods for providing insights
or metrics in connection with provisioning applications and/or
desktop sessions to end-users. Network devices (e.g., appliances,
intermediary devices, gateways, proxy devices or middle-boxes) can
gather insights such as network-level statistics. Additional
insights (e.g., metadata and metrics) associated with virtual
applications and virtual desktops can be gathered to provide
administrators with comprehensive end-to-end real-time and/or
historical reports of performance and end-user experience (UX)
insights. Insights relating to an application or desktop session
can be used to determine and/or improve the overall health of the
infrastructure of the session, Citrix Virtual Apps and Desktops,
the applications (e.g., remote desktop application) being delivered
using the infrastructure, and/or the corresponding user
experience.
Inventors: |
Momchilov; Georgy;
(Parkland, FL) ; Alluvada; Kirankumar; (Bengaluru,
IN) ; Kann; Jong; (Santa Clara, CA) ;
Marulappa Niranjanmurthy; Jayadev; (Parkland, FL) ;
Ramamurthy; Kupuswamy; (Fort Lauderdale, FL) ;
Chetan; Corneliu; (Parkland, FL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Citrix Systems, Inc. |
Fort Lauderdale |
FL |
US |
|
|
Assignee: |
Citrix Systems, Inc.
Fort Lauderdale
FL
|
Appl. No.: |
17/536587 |
Filed: |
November 29, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16684288 |
Nov 14, 2019 |
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17536587 |
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62767947 |
Nov 15, 2018 |
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International
Class: |
H04L 12/24 20060101
H04L012/24; H04L 12/46 20060101 H04L012/46; G06F 9/455 20060101
G06F009/455; H04L 12/26 20060101 H04L012/26; H04L 29/08 20060101
H04L029/08; G06F 9/451 20060101 G06F009/451; H04L 29/06 20060101
H04L029/06 |
Claims
1. A method comprising: Identifying, by a first device, that a
channel between two other computing devices has been routed to the
first device from a second device; identifying, by the first
device, information about one or more capabilities negotiated
across the two other computing devices and the second device to
support communications of one or more metrics via the channel; and
accessing, by the first device using the information, the one or
more metrics communicated via the channel.
2. The method of claim 1, further comprising identifying, by the
first device, the information from a storage accessible to the
first device and the second device, the second device storing the
information to the storage.
3. The method of claim 1, further comprising identifying, by the
first device from the information, a type of protocol for
communicating the one or more metrics via the channel.
4. The method of claim 1, further comprising identifying, by the
first device from the information, an identifier of the
channel.
5. The method of claim 1, wherein the channel is routed to the
first device responsive to a failure of the second device.
6. The method of claim 1, further comprising identifying, by the
first device from the information, a state of one of the channel or
protocol used by the channel.
7. The method of claim 1, wherein the channel is a virtual channel
used to provide the one or metrics.
8. The method of claim 1, wherein one of the first device or the
second device is intermediary to the two other computing
devices.
9. A system comprising: a first device configured to: identify that
a channel between two other computing devices has been routed to
the first device from a second device; identify information about
one or more capabilities negotiated across the two other computing
devices and the second device to support communications of one or
more metrics via the channel; and access, using the information,
the one or more metrics communicated via the channel.
10. The system of claim 9, wherein the first device is further
configured to identify the information from a storage accessible to
the first device and the second device, the second device storing
the information to the storage.
11. The system of claim 9, wherein the first device is further
configured to identify from the information a type of protocol for
communicating the one or more metrics via the channel.
12. The system of claim 9, wherein the first device is further
configured to identify from the information an identifier of the
channel.
13. The system of claim 9, wherein the channel is routed to the
first device responsive to a failure of the second device.
14. The system of claim 9, wherein the first device is further
configured to identify from the information a state of one of the
channel or protocol used by the channel.
15. The system of claim 9, wherein the channel is a virtual channel
used to provide the one or metrics.
16. The system of claim 9, wherein one of the first device or the
second device is intermediary to the two other computing
devices.
17. A non-transitory computer readable medium storing program
instructions on a first device for causing one or more processors
of the first device to: identify that a channel between two other
computing devices has been routed to the first device from a second
device; identify information about one or more capabilities
negotiated across the two other computing devices and the second
device to support communications of one or more metrics via the
channel; and access, using the information, the one or more metrics
communicated via the channel.
18. The non-transitory computer readable medium of claim 17,
wherein the program instructions further cause the one or more
processors to identify from the information a type of protocol for
communicating the one or more metrics via the channel.
19. The non-transitory computer readable medium of claim 17,
wherein the program instructions further cause the one or more
processors to identify from the information, a state of one of the
channel or protocol used by the channel.
20. The non-transitory computer readable medium of claim 17,
wherein one of the first device or the second device is
intermediary to the two other computing devices and wherein the
channel is routed to the first device responsive to a failure of
the second device.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application is a continuation of and claims priority to
and the benefit of U.S. patent application Ser. No. 16/684,288,
titled "REAL-TIME SCALABLE VIRTUAL SESSION AND NETWORK ANALYTICS,"
and filed on Nov. 14, 2019, which claims priority under 35 U.S.C.
.sctn. 119(e) to U.S. Provisional Patent Application No.
62/767,947, titled "REAL-TIME SCALABLE VIRTUAL SESSION AND NETWORK
ANALYTICS," filed Nov. 15, 2018, which is incorporated herein by
reference in its entirety.
FIELD OF THE DISCLOSURE
[0002] The present application generally relates to communicating
insights such as application and/or desktop performance and
end-user experience insights, including but not limited to systems
and methods for real-time scalable virtual session and network
analytics.
BACKGROUND
[0003] In a network computing environment, insights and metrics
about application and/or desktop performance, and on end-user
experience, can be used to determine the health of the network
computing environment such as the associated application or desktop
delivery platform.
BRIEF SUMMARY
[0004] This summary is provided to introduce a selection of
concepts in a simplified form that are further described below in
the Detailed Description. This summary is not intended to identify
key features or essential features, nor is it intended to limit the
scope of the claims included herewith.
[0005] Described herein are systems and methods for providing
insights or metrics in connection with provisioning applications
and/or desktop sessions to end-users. Network devices (e.g.,
appliances, intermediary devices, gateways, proxy devices or
middle-boxes) such as Citrix Gateway and Citrix software-defined
wide area network (SD-WAN) devices can gather insights such as
network-level statistics. Additional insights (e.g., metadata and
metrics) associated with virtual applications and virtual desktops
can be gathered to provide administrators with comprehensive
end-to-end real-time and/or historical reports of performance and
end-user experience (UX) insights. Insights relating to an
application or desktop session can be used to determine and/or
improve the overall health of the infrastructure of the session
(e.g., XenApp/XenDesktop infrastructure), the applications (e.g.,
Microsoft Office applications, remote desktop application) being
delivered using the infrastructure, and/or the corresponding user
experience. The insights can be combined with other network-health
analysis performed by network devices, and/or processed by the
network devices (e.g. Citrix Gateway or Citrix SD-WAN). In
addition, such collective insights may be provided to a management
and triaging utility (e.g. Citrix Director), a management analytics
service, or a third party collector tool. The collective insights
and/or these tools can allow administrators to view and analyze
real-time client, host and network latency metrics, historical
reports and/or end-to-end performance data, and can allow the
administrators to troubleshoot performance and network issues.
However, to obtain the insights, the network devices may have to
perform deep parsing of virtualization protocols such as Citrix
independent computing architecture (ICA) along with some or all
virtual channels (VCs), which can demand or entail knowledge of all
underlying protocol details, and can be resource intensive.
[0006] To address these and other challenges, the present
disclosure provides embodiments of methods and systems for
providing or delivering insights of a virtual session to a network
device in a real-time, scalable and/or extensible manner. In some
embodiments, a separate or independent VC (sometimes referred to as
an App Flow VC, app flow VC or insights VC) can be established
across or between a client-side agent (e.g., desktop virtualization
client), network device(s) and a server-side agent (e.g., virtual
delivery agent (VDA)) for the transmission of insights (e.g.,
virtualization session insights). The App Flow VC can be negotiated
between these entities (e.g., between the desktop virtualization
client, network appliances and VDA). The App Flow VC can facilitate
scalable and extensible processing of insights.
[0007] Some embodiments of the present methods and system provide
or support state transition of App Flow insights or metrics
(sometimes referred to as app flow or insights) during network
device failover (e.g., high-availability failover). Certain
embodiments of the present methods and system provide or support
efficient identification and prioritization of MSI HDX streams.
Some embodiments of the present methods and system provide or
support layer 7 (L7, application layer) latency calculation and
communication independent of host processing time. Some embodiments
of the present methods and system provide or support L7 latency
calculation and communication between multiple network devices.
[0008] At least one aspect of the present disclosure is directed to
systems, methods, and non-transitory computer readable media for
negotiation and establishment of independent app flow virtual
channels. A first computing device may send a request message to a
second computing device via an intermediary device. The request
message may be indicative of a capability of the first computing
device to support an insights virtual channel (VC) between the
first computing device and the second computing device. The first
computing device may receive, responsive to the request message, a
response message. The response message may include an indication of
a capability of the second computing device and an indication of a
capability of the intermediary device, to support the insights VC.
The first computing device may establish, according to the
capabilities of the first computing device, the second computing
device and the intermediary device, the insights VC to communicate
insights for use by at least one of the first computing device, the
second computing device or the intermediary device.
[0009] In some embodiments, the request message may include a
highest of a plurality of versions of a protocol that the first
computing device can support to use the insights VC to communicate
the insights. In some embodiments, the first computing device may
establish the insights VC according to a highest of a plurality of
versions of a protocol that is supported across the first computing
device, the second computing device and the intermediary device to
use the insights VC.
[0010] In some embodiments, the first computing device may
establish a plurality of VCs between the first computing device and
the second computing device, separate from the insights VC. The
plurality of VCs may be at least one of interleaved with each other
or configured to carry compressed data. The insights VC may be at
least one of non-interleaved with any of the plurality of VCs, or
configured to carry uncompressed data.
[0011] In some embodiments, the response message may include
information associating an identifier of a protocol for
communicating data using the insights VC, with an identifier of the
insights VC or a component of the first computing device. In some
embodiments, the first computing device may identify or access the
insights VC from among a plurality of VCs, using the
information.
[0012] In some embodiments, the first computing device may access,
via the insights VC, insights from at least one of the second
computing device or the intermediary device. In some embodiments,
the insights from the intermediary device may include analytics
about a network of the intermediary device.
[0013] At least one aspect of the present disclosure is directed to
systems, methods, and non-transitory computer readable media for
state transition of app flow metrics during network appliance
failover. A first device may be intermediary between a first
computing device and a second computing device. The first device
may determine that an insights virtual channel (VC) established
between the first computing device and the second computing device,
is re-routed to the first device from a second device intermediary
between the first computing device and the second computing device.
The first device may receive protocol state of the insights VC. The
protocol state may include information associating (i) an
identifier of a protocol for communicating insights using the
insights VC, with (ii) an identifier of the insights VC or a
component of the first computing device. The first device may
access, using the received protocol state, the insights
communicated via the insights VC, that are from at least one of the
first computing device or the second computing device.
[0014] In some embodiments, the first device may receive the
protocol state of the insights VC from a shared storage. The
protocol state may be saved by the second device in the shared
storage. In some embodiments, the protocol state of the insights VC
may include capabilities negotiated across the first computing
device, the second computing device and the second device, to
support communicating the insights via the insights VC. In some
embodiments, the protocol state of the insights VC may include at
least one of a protocol name of the insights VC, information about
event of the insights VC, and data points of the insights VC.
[0015] In some embodiments, the device may receive the protocol
state of the insights VC by identifying the protocol state using a
protocol-level identifier. In some embodiments, the device may
receive the protocol state of the insights VC by accessing the
identified protocol state from the shared storage. In some
embodiments, the protocol state of the insights VC may include at
least one of an encryption method, an encryption key, or a last
encrypted byte.
[0016] In some embodiments, the first device may re-synchronize, at
a common gateway protocol level, packets transmitted or received
via the insights VC. In some embodiments, the first device may
initialize or re-initialize using a tunneling protocol. In some
embodiments, the first device may receive the protocol state of the
insights VC from a VC agent executing at the first computing device
or the second computing device. In some embodiments, the protocol
state of the insights VC may include capabilities negotiated across
the first computing device, the second computing device and the
second device, to support communicating the insights via the
insights VC.
[0017] At least one aspect of the present disclosure is directed to
systems, methods, and non-transitory computer readable media for
identification and prioritization of Multi-stream ICA (MSI) HDX
streams. A first device may establish a plurality of data streams
between the first device and a second device. Each of the data
streams may include at least one virtual channel (VC), wherein a
first data stream of the plurality of data streams includes an
insights VC. The first device may determine, for each corresponding
data stream of the plurality of data streams, an identifier and a
priority of the corresponding data stream. The first device may
send, for each corresponding data stream of the plurality of data
streams, information regarding the identifier and the priority of
the corresponding data stream, in the corresponding data stream, to
be accessed by a computing device intermediary between the first
device and the second device.
[0018] In some embodiments, the first device may send, in the
corresponding data stream, the information including a globally
unique identifier of a session of the plurality of data streams. In
some embodiments, the first device may send, in the corresponding
data stream, the information including a type of the corresponding
data stream. In some embodiments, the type of the corresponding
data stream may correspond to a primary data stream or a secondary
data stream.
[0019] In some embodiments, the first device may determine, for
each corresponding data stream of the plurality of data streams, an
updated priority of the corresponding data stream. In some
embodiments, the first device may send, for each corresponding data
stream of the plurality of data streams, information regarding the
identifier and the updated priority of the corresponding data
stream, in the corresponding data stream.
[0020] In some embodiments, the first device may communicate data
in the plurality of data streams via a single port to server or a
client device. In some embodiments, the first device may send the
information responsive to establishing one of the plurality of data
streams.
[0021] At least one aspect of the present disclosure is directed to
systems, methods, and non-transitory computer readable media for
application layer (L7) calculation and communication independent of
server host processing time. A device intermediary between a client
device and a server may incorporate a token to a first packet at a
time T1. The device may cause the server to receive the token in
the first packet at a time T2, and to determine a duration D for
generating a payload relative to T2. The device may receive a
second packet with the payload at a time T3. The device may
determine a round-trip network time according to T3-T1-D.
[0022] In some embodiments, the device may receive the first packet
from the client device. In some embodiments, the device may record
the time T1. In some embodiments, the device may cause a driver of
the server to receive the token in the first packet at the time T2.
In some embodiments, the device may cause an application of the
server to generate the payload responsive to the first packet. In
some embodiments, the device may cause the driver of the server to
receive the payload at a time T2a, wherein D=T2a-T2.
[0023] In some embodiments, the payload may be in Javascript object
notation (JSON) format. In some embodiments, the device may receive
the second packet in an insights virtual channel (VC) established
between the client device and the server. In some embodiments, the
insights VC may be non-interleaved with other VCs established
between the client device and the server, and the payload in the
second packet comprises uncompressed data.
[0024] In some embodiments, the device may incorporate an
identification of the device in the first packet. In some
embodiments, the device may determine the round-trip network time
if the second packet includes the identification of the device. In
some embodiments, the device may receive a third packet from the
server. In some embodiments, the device may bypass a determination
of the round-trip network time according to the third packet, if
the identification of the device is absent in the third packet.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0025] Objects, aspects, features, and advantages of embodiments
disclosed herein will become more fully apparent from the following
detailed description, the appended claims, and the accompanying
drawing figures in which like reference numerals identify similar
or identical elements. Reference numerals that are introduced in
the specification in association with a drawing figure may be
repeated in one or more subsequent figures without additional
description in the specification in order to provide context for
other features, and not every element may be labeled in every
figure. The drawing figures are not necessarily to scale, emphasis
instead being placed upon illustrating embodiments, principles and
concepts. The drawings are not intended to limit the scope of the
claims included herewith.
[0026] FIG. 1A is a block diagram of a network computing system, in
accordance with an illustrative embodiment;
[0027] FIG. 1B is a block diagram of a network computing system for
delivering a computing environment from a server to a client via an
appliance, in accordance with an illustrative embodiment;
[0028] FIG. 1C is a block diagram of a computing device, in
accordance with an illustrative embodiment;
[0029] FIG. 2 is a block diagram of an appliance for processing
communications between a client and a server, in accordance with an
illustrative embodiment;
[0030] FIG. 3 is a block diagram of a virtualization environment,
in accordance with an illustrative embodiment;
[0031] FIG. 4 is a block diagram of a cluster system, in accordance
with an illustrative embodiment;
[0032] FIG. 5 is a block diagram of an embodiment of a system for
providing or using a virtual channel to provide insights, according
to an illustrative embodiment;
[0033] FIG. 6 is a diagram of an embodiment of a system and method
for providing or using a virtual channel to provide insights,
according to an illustrative embodiment;
[0034] FIG. 7 is a block diagram of an embodiment of a system for
App Flow data points collection and transmission, according to an
illustrative embodiment;
[0035] FIGS. 8-10 provide example charts comprising test results
comparing implementations with and without using an App Flow
virtual channel for insights, according to an illustrative
embodiment;
[0036] FIG. 11 is a flow diagram of a method of establishing
independent application flow virtual channels, according to
illustrative embodiments;
[0037] FIG. 12 is a block diagram of a system of transitioning
application flow metrics during appliance failover, according to
illustrative embodiments;
[0038] FIG. 13 is a flow diagram of a method of transitioning
application flow metrics during appliance failover, according to
illustrative embodiments;
[0039] FIG. 14 is a block diagram of an embodiment of a system for
providing multi-stream ICA (MSI) between client-side and
server-side network devices, according to illustrative
embodiments;
[0040] FIG. 15 is a flow diagram of a method of prioritizing data
streams for virtual channels, according to illustrative
embodiments;
[0041] FIG. 16 is a diagram illustrating a method for calculating
latency independent of server processing time, according to
illustrative embodiments; and
[0042] FIG. 17 is a flow diagram of a method of calculating latency
in application layer (L7) communications independent of host server
processing time, according to illustrative embodiments.
[0043] The features and advantages of the present solution will
become more apparent from the detailed description set forth below
when taken in conjunction with the drawings, in which like
reference characters identify corresponding elements throughout. In
the drawings, like reference numbers generally indicate identical,
functionally similar, and/or structurally similar elements.
DETAILED DESCRIPTION
[0044] For purposes of reading the description of the various
embodiments below, the following descriptions of the sections of
the specification and their respective contents may be helpful:
[0045] Section A describes a network environment and computing
environment which may be useful for practicing embodiments
described herein;
[0046] Section B describes embodiments of systems and methods for
delivering a computing environment to a remote user;
[0047] Section C describes embodiments of systems and methods for
virtualizing an application delivery controller;
[0048] Section D describes embodiments of systems and methods for
providing a clustered appliance architecture environment; and
[0049] Section E describes embodiments of systems and methods of
providing or using a virtual channel to provide insights.
A. Network and Computing Environment
[0050] Referring to FIG. 1A, an illustrative network environment
100 is depicted. Network environment 100 may include one or more
clients 102(1)-102(n) (also generally referred to as local
machine(s) 102 or client(s) 102) in communication with one or more
servers 106(1)-106(n) (also generally referred to as remote
machine(s) 106 or server(s) 106) via one or more networks
104(1)-104n (generally referred to as network(s) 104). In some
embodiments, a client 102 may communicate with a server 106 via one
or more appliances 200(1)-200n (generally referred to as
appliance(s) 200 or gateway(s) 200).
[0051] Although the embodiment shown in FIG. 1A shows one or more
networks 104 between clients 102 and servers 106, in other
embodiments, clients 102 and servers 106 may be on the same network
104. The various networks 104 may be the same type of network or
different types of networks. For example, in some embodiments,
network 104(1) may be a private network such as a local area
network (LAN) or a company Intranet, while network 104(2) and/or
network 104(n) may be a public network, such as a wide area network
(WAN) or the Internet. In other embodiments, both network 104(1)
and network 104(n) may be private networks. Networks 104 may employ
one or more types of physical networks and/or network topologies,
such as wired and/or wireless networks, and may employ one or more
communication transport protocols, such as transmission control
protocol (TCP), internet protocol (IP), user datagram protocol
(UDP) or other similar protocols.
[0052] As shown in FIG. 1A, one or more appliances 200 may be
located at various points or in various communication paths of
network environment 100. For example, appliance 200 may be deployed
between two networks 104(1) and 104(2), and appliances 200 may
communicate with one another to work in conjunction to, for
example, accelerate network traffic between clients 102 and servers
106. In other embodiments, the appliance 200 may be located on a
network 104. For example, appliance 200 may be implemented as part
of one of clients 102 and/or servers 106. In an embodiment,
appliance 200 may be implemented as a network device such as
NetScaler.RTM. products sold by Citrix Systems, Inc. of Fort
Lauderdale, Fla.
[0053] As shown in FIG. 1A, one or more servers 106 may operate as
a server farm 38. Servers 106 of server farm 38 may be logically
grouped, and may either be geographically co-located (e.g., on
premises) or geographically dispersed (e.g., cloud based) from
clients 102 and/or other servers 106. In an embodiment, server farm
38 executes one or more applications on behalf of one or more of
clients 102 (e.g., as an application server), although other uses
are possible, such as a file server, gateway server, proxy server,
or other similar server uses. Clients 102 may seek access to hosted
applications on servers 106.
[0054] As shown in FIG. 1A, in some embodiments, appliances 200 may
include, be replaced by, or be in communication with, one or more
additional appliances, such as WAN optimization appliances
205(1)-205(n), referred to generally as WAN optimization
appliance(s) 205. For example, WAN optimization appliance 205 may
accelerate, cache, compress or otherwise optimize or improve
performance, operation, flow control, or quality of service of
network traffic, such as traffic to and/or from a WAN connection,
such as optimizing Wide Area File Services (WAFS), accelerating
Server Message Block (SMB) or Common Internet File System (CIFS).
In some embodiments, appliance 205 may be a performance enhancing
proxy or a WAN optimization controller. In one embodiment,
appliance 205 may be implemented as CloudBridge.RTM. products sold
by Citrix Systems, Inc. of Fort Lauderdale, Fla.
[0055] Referring to FIG. 1B, an example network environment 100'
for delivering and/or operating a computing network environment on
a client 102 is shown. As shown in FIG. 1B, a server 106 may
include an application delivery system 190 for delivering a
computing environment, application, and/or data files to one or
more clients 102. Client 102 may include client agent 120 and
computing environment 15. Computing environment 15 may execute or
operate an application, 16, that accesses, processes or uses a data
file 17. Computing environment 15, application 16 and/or data file
17 may be delivered to the client 102 via appliance 200 and/or the
server 106.
[0056] Appliance 200 may accelerate delivery of all or a portion of
computing environment 15 to a client 102, for example by the
application delivery system 190. For example, appliance 200 may
accelerate delivery of a streaming application and data file
processable by the application from a data center to a remote user
location by accelerating transport layer traffic between a client
102 and a server 106. Such acceleration may be provided by one or
more techniques, such as: 1) transport layer connection pooling, 2)
transport layer connection multiplexing, 3) transport control
protocol buffering, 4) compression, 5) caching, or other
techniques. Appliance 200 may also provide load balancing of
servers 106 to process requests from clients 102, act as a proxy or
access server to provide access to the one or more servers 106,
provide security and/or act as a firewall between a client 102 and
a server 106, provide Domain Name Service (DNS) resolution, provide
one or more virtual servers or virtual internet protocol servers,
and/or provide a secure virtual private network (VPN) connection
from a client 102 to a server 106, such as a secure socket layer
(SSL) VPN connection and/or provide encryption and decryption
operations.
[0057] Application delivery management system 190 may deliver
computing environment 15 to a user (e.g., client 102), remote or
otherwise, based on authentication and authorization policies
applied by policy engine 195. A remote user may obtain a computing
environment and access to server stored applications and data files
from any network-connected device (e.g., client 102). For example,
appliance 200 may request an application and data file from server
106. In response to the request, application delivery system 190
and/or server 106 may deliver the application and data file to
client 102, for example via an application stream to operate in
computing environment 15 on client 102, or via a remote-display
protocol or otherwise via remote-based or server-based computing.
In an embodiment, application delivery system 190 may be
implemented as any portion of the Citrix Workspace Suite.TM. by
Citrix Systems, Inc., such as XenApp.RTM. or XenDesktop.RTM..
[0058] Policy engine 195 may control and manage the access to, and
execution and delivery of, applications. For example, policy engine
195 may determine the one or more applications a user or client 102
may access and/or how the application should be delivered to the
user or client 102, such as a server-based computing, streaming or
delivering the application locally to the client 50 for local
execution.
[0059] For example, in operation, a client 102 may request
execution of an application (e.g., application 16') and application
delivery system 190 of server 106 determines how to execute
application 16', for example based upon credentials received from
client 102 and a user policy applied by policy engine 195
associated with the credentials. For example, application delivery
system 190 may enable client 102 to receive application-output data
generated by execution of the application on a server 106, may
enable client 102 to execute the application locally after
receiving the application from server 106, or may stream the
application via network 104 to client 102. For example, in some
embodiments, the application may be a server-based or a
remote-based application executed on server 106 on behalf of client
102. Server 106 may display output to client 102 using a
thin-client or remote-display protocol, such as the Independent
Computing Architecture (ICA) protocol by Citrix Systems, Inc. of
Fort Lauderdale, Fla. The application may be any application
related to real-time data communications, such as applications for
streaming graphics, streaming video and/or audio or other data,
delivery of remote desktops or workspaces or hosted services or
applications, for example infrastructure as a service (IaaS),
workspace as a service (WaaS), software as a service (SaaS) or
platform as a service (PaaS).
[0060] One or more of servers 106 may include a performance
monitoring service or agent 197. In some embodiments, a dedicated
one or more servers 106 may be employed to perform performance
monitoring. Performance monitoring may be performed using data
collection, aggregation, analysis, management and reporting, for
example by software, hardware or a combination thereof. Performance
monitoring may include one or more agents for performing
monitoring, measurement and data collection activities on clients
102 (e.g., client agent 120), servers 106 (e.g., agent 197) or an
appliance 200 and/or 205 (agent not shown). In general, monitoring
agents (e.g., 120 and/or 197) execute transparently (e.g., in the
background) to any application and/or user of the device. In some
embodiments, monitoring agent 197 includes any of the product
embodiments referred to as EdgeSight by Citrix Systems, Inc. of
Fort Lauderdale, Fla.
[0061] The monitoring agents 120 and 197 may monitor, measure,
collect, and/or analyze data on a predetermined frequency, based
upon an occurrence of given event(s), or in real time during
operation of network environment 100. The monitoring agents may
monitor resource consumption and/or performance of hardware,
software, and/or communications resources of clients 102, networks
104, appliances 200 and/or 205, and/or servers 106. For example,
network connections such as a transport layer connection, network
latency, bandwidth utilization, end-user response times,
application usage and performance, session connections to an
application, cache usage, memory usage, processor usage, storage
usage, database transactions, client and/or server utilization,
active users, duration of user activity, application crashes,
errors, or hangs, the time required to log-in to an application, a
server, or the application delivery system, and/or other
performance conditions and metrics may be monitored.
[0062] The monitoring agents 120 and 197 may provide application
performance management for application delivery system 190. For
example, based upon one or more monitored performance conditions or
metrics, application delivery system 190 may be dynamically
adjusted, for example periodically or in real-time, to optimize
application delivery by servers 106 to clients 102 based upon
network environment performance and conditions.
[0063] In described embodiments, clients 102, servers 106, and
appliances 200 and 205 may be deployed as and/or executed on any
type and form of computing device, such as any desktop computer,
laptop computer, or mobile device capable of communication over at
least one network and performing the operations described herein.
For example, clients 102, servers 106 and/or appliances 200 and 205
may each correspond to one computer, a plurality of computers, or a
network of distributed computers such as computer 101 shown in FIG.
1C.
[0064] As shown in FIG. 1C, computer 101 may include one or more
processors 103, volatile memory 122 (e.g., RAM), non-volatile
memory 128 (e.g., one or more hard disk drives (HDDs) or other
magnetic or optical storage media, one or more solid state drives
(SSDs) such as a flash drive or other solid state storage media,
one or more hybrid magnetic and solid state drives, and/or one or
more virtual storage volumes, such as a cloud storage, or a
combination of such physical storage volumes and virtual storage
volumes or arrays thereof), user interface (UI) 123, one or more
communications interfaces 118, and communication bus 150. User
interface 123 may include graphical user interface (GUI) 124 (e.g.,
a touchscreen, a display, etc.) and one or more input/output (I/O)
devices 126 (e.g., a mouse, a keyboard, etc.). Non-volatile memory
128 stores operating system 115, one or more applications 116, and
data 117 such that, for example, computer instructions of operating
system 115 and/or applications 116 are executed by processor(s) 103
out of volatile memory 122. Data may be entered using an input
device of GUI 124 or received from I/O device(s) 126. Various
elements of computer 101 may communicate via communication bus 150.
Computer 101 as shown in FIG. 1C is shown merely as an example, as
clients 102, servers 106 and/or appliances 200 and 205 may be
implemented by any computing or processing environment and with any
type of machine or set of machines that may have suitable hardware
and/or software capable of operating as described herein.
[0065] Processor(s) 103 may be implemented by one or more
programmable processors executing one or more computer programs to
perform the functions of the system. As used herein, the term
"processor" describes an electronic circuit that performs a
function, an operation, or a sequence of operations. The function,
operation, or sequence of operations may be hard coded into the
electronic circuit or soft coded by way of instructions held in a
memory device. A "processor" may perform the function, operation,
or sequence of operations using digital values or using analog
signals. In some embodiments, the "processor" can be embodied in
one or more application specific integrated circuits (ASICs),
microprocessors, digital signal processors, microcontrollers, field
programmable gate arrays (FPGAs), programmable logic arrays (PLAs),
multi-core processors, or general-purpose computers with associated
memory. The "processor" may be analog, digital or mixed-signal. In
some embodiments, the "processor" may be one or more physical
processors or one or more "virtual" (e.g., remotely located or
"cloud") processors.
[0066] Communications interfaces 118 may include one or more
interfaces to enable computer 101 to access a computer network such
as a LAN, a WAN, or the Internet through a variety of wired and/or
wireless or cellular connections.
[0067] In described embodiments, a first computing device 101 may
execute an application on behalf of a user of a client computing
device (e.g., a client 102), may execute a virtual machine, which
provides an execution session within which applications execute on
behalf of a user or a client computing device (e.g., a client 102),
such as a hosted desktop session, may execute a terminal services
session to provide a hosted desktop environment, or may provide
access to a computing environment including one or more of: one or
more applications, one or more desktop applications, and one or
more desktop sessions in which one or more applications may
execute.
B. Appliance Architecture
[0068] FIG. 2 shows an example embodiment of appliance 200. As
described herein, appliance 200 may be implemented as a server,
gateway, router, switch, bridge or other type of computing or
network device. As shown in FIG. 2, an embodiment of appliance 200
may include a hardware layer 206 and a software layer 205 divided
into a user space 202 and a kernel space 204. Hardware layer 206
provides the hardware elements upon which programs and services
within kernel space 204 and user space 202 are executed and allow
programs and services within kernel space 204 and user space 202 to
communicate data both internally and externally with respect to
appliance 200. As shown in FIG. 2, hardware layer 206 may include
one or more processing units 262 for executing software programs
and services, memory 264 for storing software and data, network
ports 266 for transmitting and receiving data over a network, and
encryption processor 260 for encrypting and decrypting data such as
in relation to Secure Socket Layer (SSL) or Transport Layer
Security (TLS) processing of data transmitted and received over the
network.
[0069] An operating system of appliance 200 allocates, manages, or
otherwise segregates the available system memory into kernel space
204 and user space 202. Kernel space 204 is reserved for running
kernel 230, including any device drivers, kernel extensions or
other kernel related software. As known to those skilled in the
art, kernel 230 is the core of the operating system, and provides
access, control, and management of resources and hardware-related
elements of application. Kernel space 204 may also include a number
of network services or processes working in conjunction with cache
manager 232.
[0070] Appliance 200 may include one or more network stacks 267,
such as a TCP/IP based stack, for communicating with client(s) 102,
server(s) 106, network(s) 104, and/or other appliances 200 or 205.
For example, appliance 200 may establish and/or terminate one or
more transport layer connections between clients 102 and servers
106. Each network stack 267 may include a buffer for queuing one or
more network packets for transmission by appliance 200.
[0071] Kernel space 204 may include cache manager 232, packet
engine 240, encryption engine 234, policy engine 236 and
compression engine 238. In other words, one or more of processes
232, 240, 234, 236 and 238 run in the core address space of the
operating system of appliance 200, which may reduce the number of
data transactions to and from the memory and/or context switches
between kernel mode and user mode, for example since data obtained
in kernel mode may not need to be passed or copied to a user
process, thread or user level data structure.
[0072] Cache manager 232 may duplicate original data stored
elsewhere or data previously computed, generated or transmitted to
reduce the access time of the data. In some embodiments, the cache
manager 232 may be a data object in memory 264 of appliance 200, or
may be a physical memory having a faster access time than memory
264.
[0073] Policy engine 236 may include a statistical engine or other
configuration mechanism to allow a user to identify, specify,
define or configure a caching policy and access, control and
management of objects, data or content being cached by appliance
200, and define or configure security, network traffic, network
access, compression or other functions performed by appliance
200.
[0074] Encryption engine 234 may process any security related
protocol, such as SSL or TLS. For example, encryption engine 234
may encrypt and decrypt network packets, or any portion thereof,
communicated via appliance 200, may setup or establish SSL, TLS or
other secure connections, for example between client 102, server
106, and/or other appliances 200 or 205. In some embodiments,
encryption engine 234 may use a tunneling protocol to provide a VPN
between a client 102 and a server 106. In some embodiments,
encryption engine 234 is in communication with encryption processor
260. Compression engine 238 compresses network packets
bi-directionally between clients 102 and servers 106 and/or between
one or more appliances 200.
[0075] Packet engine 240 may manage kernel-level processing of
packets received and transmitted by appliance 200 via network
stacks 267 to send and receive network packets via network ports
266. Packet engine 240 may operate in conjunction with encryption
engine 234, cache manager 232, policy engine 236 and compression
engine 238, for example to perform encryption/decryption, traffic
management such as request-level content switching and
request-level cache redirection, and compression and decompression
of data.
[0076] User space 202 is a memory area or portion of the operating
system used by user mode applications or programs otherwise running
in user mode. A user mode application may not access kernel space
204 directly and uses service calls in order to access kernel
services. User space 202 may include graphical user interface (GUI)
210, a command line interface (CLI) 212, shell services 214, health
monitor 216, and daemon services 218. GUI 210 and CLI 212 enable a
system administrator or other user to interact with and control the
operation of appliance 200, such as via the operating system of
appliance 200. Shell services 214 include programs, services,
tasks, processes or executable instructions to support interaction
with appliance 200 by a user via the GUI 210 and/or CLI 212.
[0077] Health monitor 216 monitors, checks, reports and ensures
that network systems are functioning properly and that users are
receiving requested content over a network, for example by
monitoring activity of appliance 200. In some embodiments, health
monitor 216 intercepts and inspects any network traffic passed via
appliance 200. For example, health monitor 216 may interface with
one or more of encryption engine 234, cache manager 232, policy
engine 236, compression engine 238, packet engine 240, daemon
services 218, and shell services 214 to determine a state, status,
operating condition, or health of any portion of the appliance 200.
Further, health monitor 216 may determine whether a program,
process, service or task is active and currently running, check
status, error or history logs provided by any program, process,
service or task to determine any condition, status or error with
any portion of appliance 200. Additionally, health monitor 216 may
measure and monitor the performance of any application, program,
process, service, task or thread executing on appliance 200.
[0078] Daemon services 218 are programs that run continuously or in
the background and handle periodic service requests received by
appliance 200. In some embodiments, a daemon service may forward
the requests to other programs or processes, such as another daemon
service 218 as appropriate.
[0079] As described herein, appliance 200 may relieve servers 106
of much of the processing load caused by repeatedly opening and
closing transport layer connections to clients 102 by opening one
or more transport layer connections with each server 106 and
maintaining these connections to allow repeated data accesses by
clients via the Internet (e.g., "connection pooling"). To perform
connection pooling, appliance 200 may translate or multiplex
communications by modifying sequence numbers and acknowledgment
numbers at the transport layer protocol level (e.g., "connection
multiplexing"). Appliance 200 may also provide switching or load
balancing for communications between the client 102 and server
106.
[0080] As described herein, each client 102 may include client
agent 120 for establishing and exchanging communications with
appliance 200 and/or server 106 via a network 104. Client 102 may
have installed and/or execute one or more applications that are in
communication with network 104. Client agent 120 may intercept
network communications from a network stack used by the one or more
applications. For example, client agent 120 may intercept a network
communication at any point in a network stack and redirect the
network communication to a destination desired, managed or
controlled by client agent 120, for example to intercept and
redirect a transport layer connection to an IP address and port
controlled or managed by client agent 120. Thus, client agent 120
may transparently intercept any protocol layer below the transport
layer, such as the network layer, and any protocol layer above the
transport layer, such as the session, presentation or application
layers. Client agent 120 can interface with the transport layer to
secure, optimize, accelerate, route or load-balance any
communications provided via any protocol carried by the transport
layer.
[0081] In some embodiments, client agent 120 is implemented as an
Independent Computing Architecture (ICA) client developed by Citrix
Systems, Inc. of Fort Lauderdale, Fla. Client agent 120 may perform
acceleration, streaming, monitoring, and/or other operations. For
example, client agent 120 may accelerate streaming an application
from a server 106 to a client 102. Client agent 120 may also
perform end-point detection/scanning and collect end-point
information about client 102 for appliance 200 and/or server 106.
Appliance 200 and/or server 106 may use the collected information
to determine and provide access, authentication and authorization
control of the client's connection to network 104. For example,
client agent 120 may identify and determine one or more client-side
attributes, such as: the operating system and/or a version of an
operating system, a service pack of the operating system, a running
service, a running process, a file, presence or versions of various
applications of the client, such as antivirus, firewall, security,
and/or other software.
C. Systems and Methods for Providing Virtualized Application
Delivery Controller
[0082] Referring now to FIG. 3, a block diagram of a virtualized
environment 300 is shown. As shown, a computing device 302 in
virtualized environment 300 includes a virtualization layer 303, a
hypervisor layer 304, and a hardware layer 307. Hypervisor layer
304 includes one or more hypervisors (or virtualization managers)
301 that allocates and manages access to a number of physical
resources in hardware layer 307 (e.g., physical processor(s) 321
and physical disk(s) 328) by at least one virtual machine (VM)
(e.g., one of VMs 306) executing in virtualization layer 303. Each
VM 306 may include allocated virtual resources such as virtual
processors 332 and/or virtual disks 342, as well as virtual
resources such as virtual memory and virtual network interfaces. In
some embodiments, at least one of VMs 306 may include a control
operating system (e.g., 305) in communication with hypervisor 301
and used to execute applications for managing and configuring other
VMs (e.g., guest operating systems 310) on device 302.
[0083] In general, hypervisor(s) 301 may provide virtual resources
to an operating system of VMs 306 in any manner that simulates the
operating system having access to a physical device. Thus,
hypervisor(s) 301 may be used to emulate virtual hardware,
partition physical hardware, virtualize physical hardware, and
execute virtual machines that provide access to computing
environments. In an illustrative embodiment, hypervisor(s) 301 may
be implemented as a XEN hypervisor, for example as provided by the
open source Xen.org community. In an illustrative embodiment,
device 302 executing a hypervisor that creates a virtual machine
platform on which guest operating systems may execute is referred
to as a host server. In such an embodiment, device 302 may be
implemented as a XEN server as provided by Citrix Systems, Inc., of
Fort Lauderdale, Fla.
[0084] Hypervisor 301 may create one or more VMs 306 in which an
operating system (e.g., control operating system 305 and/or guest
operating system 310) executes. For example, the hypervisor 301
loads a virtual machine image to create VMs 306 to execute an
operating system. Hypervisor 301 may present VMs 306 with an
abstraction of hardware layer 307, and/or may control how physical
capabilities of hardware layer 307 are presented to VMs 306. For
example, hypervisor(s) 301 may manage a pool of resources
distributed across multiple physical computing devices.
[0085] In some embodiments, one of VMs 306 (e.g., the VM executing
control operating system 305) may manage and configure other of VMs
306, for example by managing the execution and/or termination of a
VM and/or managing allocation of virtual resources to a VM. In
various embodiments, VMs may communicate with hypervisor(s) 301
and/or other VMs via, for example, one or more Application
Programming Interfaces (APIs), shared memory, and/or other
techniques.
[0086] In general, VMs 306 may provide a user of device 302 with
access to resources within virtualized computing environment 300,
for example, one or more programs, applications, documents, files,
desktop and/or computing environments, or other resources. In some
embodiments, VMs 306 may be implemented as fully virtualized VMs
that are not aware that they are virtual machines (e.g., a Hardware
Virtual Machine or HVM). In other embodiments, the VM may be aware
that it is a virtual machine, and/or the VM may be implemented as a
paravirtualized (PV) VM.
[0087] Although shown in FIG. 3 as including a single virtualized
device 302, virtualized environment 300 may include a plurality of
networked devices in a system in which at least one physical host
executes a virtual machine. A device on which a VM executes may be
referred to as a physical host and/or a host machine. For example,
appliance 200 may be additionally or alternatively implemented in a
virtualized environment 300 on any computing device, such as a
client 102, server 106 or appliance 200. Virtual appliances may
provide functionality for availability, performance, health
monitoring, caching and compression, connection multiplexing and
pooling and/or security processing (e.g., firewall, VPN,
encryption/decryption, etc.), similarly as described in regard to
appliance 200.
[0088] In some embodiments, a server may execute multiple virtual
machines 306, for example on various cores of a multi-core
processing system and/or various processors of a multiple processor
device. For example, although generally shown herein as
"processors" (e.g., in FIGS. 1C, 2 and 3), one or more of the
processors may be implemented as either single- or multi-core
processors to provide a multi-threaded, parallel architecture
and/or multi-core architecture. Each processor and/or core may have
or use memory that is allocated or assigned for private or local
use that is only accessible by that processor/core, and/or may have
or use memory that is public or shared and accessible by multiple
processors/cores. Such architectures may allow work, task, load or
network traffic distribution across one or more processors and/or
one or more cores (e.g., by functional parallelism, data
parallelism, flow-based data parallelism, etc.).
[0089] Further, instead of (or in addition to) the functionality of
the cores being implemented in the form of a physical
processor/core, such functionality may be implemented in a
virtualized environment (e.g., 300) on a client 102, server 106 or
appliance 200, such that the functionality may be implemented
across multiple devices, such as a cluster of computing devices, a
server farm or network of computing devices, etc. The various
processors/cores may interface or communicate with each other using
a variety of interface techniques, such as core to core messaging,
shared memory, kernel APIs, etc.
[0090] In embodiments employing multiple processors and/or multiple
processor cores, described embodiments may distribute data packets
among cores or processors, for example to balance the flows across
the cores. For example, packet distribution may be based upon
determinations of functions performed by each core, source and
destination addresses, and/or whether: a load on the associated
core is above a predetermined threshold; the load on the associated
core is below a predetermined threshold; the load on the associated
core is less than the load on the other cores; or any other metric
that can be used to determine where to forward data packets based
in part on the amount of load on a processor.
[0091] For example, data packets may be distributed among cores or
processes using receive-side scaling (RSS) in order to process
packets using multiple processors/cores in a network. RSS generally
allows packet processing to be balanced across multiple
processors/cores while maintaining in-order delivery of the
packets. In some embodiments, RSS may use a hashing scheme to
determine a core or processor for processing a packet.
[0092] The RSS may generate hash values from any type and form of
input, such as a sequence of values. This sequence of values can
include any portion of the network packet, such as any header,
field or payload of network packet, and include any tuples of
information associated with a network packet or data flow, such as
addresses and ports. The hash result or any portion thereof may be
used to identify a processor, core, engine, etc., for distributing
a network packet, for example via a hash table, indirection table,
or other mapping technique.
D. Systems and Methods for Providing a Distributed Cluster
Architecture
[0093] Although shown in FIGS. 1A and 1B as being single
appliances, appliances 200 may be implemented as one or more
distributed or clustered appliances. Individual computing devices
or appliances may be referred to as nodes of the cluster. A
centralized management system may perform load balancing,
distribution, configuration, or other tasks to allow the nodes to
operate in conjunction as a single computing system. Such a cluster
may be viewed as a single virtual appliance or computing device.
FIG. 4 shows a block diagram of an illustrative computing device
cluster or appliance cluster 400. A plurality of appliances 200 or
other computing devices (e.g., nodes) may be joined into a single
cluster 400. Cluster 400 may operate as an application server,
network storage server, backup service, or any other type of
computing device to perform many of the functions of appliances 200
and/or 205.
[0094] In some embodiments, each appliance 200 of cluster 400 may
be implemented as a multi-processor and/or multi-core appliance, as
described herein. Such embodiments may employ a two-tier
distribution system, with one appliance if the cluster distributing
packets to nodes of the cluster, and each node distributing packets
for processing to processors/cores of the node. In many
embodiments, one or more of appliances 200 of cluster 400 may be
physically grouped or geographically proximate to one another, such
as a group of blade servers or rack mount devices in a given
chassis, rack, and/or data center. In some embodiments, one or more
of appliances 200 of cluster 400 may be geographically distributed,
with appliances 200 not physically or geographically co-located. In
such embodiments, geographically remote appliances may be joined by
a dedicated network connection and/or VPN. In geographically
distributed embodiments, load balancing may also account for
communications latency between geographically remote
appliances.
[0095] In some embodiments, cluster 400 may be considered a virtual
appliance, grouped via common configuration, management, and
purpose, rather than as a physical group. For example, an appliance
cluster may comprise a plurality of virtual machines or processes
executed by one or more servers.
[0096] As shown in FIG. 4, appliance cluster 400 may be coupled to
a client-side network 104 via client data plane 402, for example to
transfer data between clients 102 and appliance cluster 400. Client
data plane 402 may be implemented a switch, hub, router, or other
similar network device internal or external to cluster 400 to
distribute traffic across the nodes of cluster 400. For example,
traffic distribution may be performed based on equal-cost
multi-path (ECMP) routing with next hops configured with appliances
or nodes of the cluster, open-shortest path first (OSPF), stateless
hash-based traffic distribution, link aggregation (LAG) protocols,
or any other type and form of flow distribution, load balancing,
and routing.
[0097] Appliance cluster 400 may be coupled to a second network
104' via server data plane 404. Similar to client data plane 402,
server data plane 404 may be implemented as a switch, hub, router,
or other network device that may be internal or external to cluster
400. In some embodiments, client data plane 402 and server data
plane 404 may be merged or combined into a single device.
[0098] In some embodiments, each appliance 200 of cluster 400 may
be connected via an internal communication network or backplane
406. Backplane 406 may enable inter-node or inter-appliance control
and configuration messages, for inter-node forwarding of traffic,
and/or for communicating configuration and control traffic from an
administrator or user to cluster 400. In some embodiments,
backplane 406 may be a physical network, a VPN or tunnel, or a
combination thereof.
E. Systems and Methods for Providing and Using a Virtual Channel to
Provide Insights
[0099] Described herein are systems and methods for providing
insights or metrics in connection with provisioning applications
and/or desktop sessions to end-users. Network devices (e.g.,
appliances, intermediary devices, gateways, proxy devices or
middle-boxes) such as Citrix Gateway and Citrix software-defined
wide area network (SD-WAN) devices can gather insights such as
network-level statistics. Additional insights (e.g., metadata and
metrics) associated with virtual applications and virtual desktops
can be gathered to provide administrators with comprehensive
end-to-end real-time and/or historical reports of performance and
end-user experience (UX) insights. In some embodiments, to obtain
the insights, the network devices may have to perform deep parsing
of virtualization and other protocols such as Citrix independent
computing architecture (ICA), remote desktop protocol (RDP), or
Citrix high definition experience (HDX), along with some or all
associated virtual channels (VCs).
[0100] This deep parsing can demand or entail knowledge of all
underlying protocol details, and can be resource intensive. The
effort for a network device to deeply parse, decrypt and/or
decompress traffic (e.g., HDX traffic) can hurt the scalability of
the network device and can significantly increase the cost of
supporting (e.g., HDX specific) insights. These can be memory and
CPU intensive operations that directly affect the number of
connections (e.g., ICA connections) that a network device (e.g.,
Citrix Gateway or SD-WAN appliance) can support at a time. Deep
parsing of such traffic can be a memory and CPU intensive
operation, mainly because of the stateful decompression of the ICA
stream. "Stateful" can refer to maintaining, tracking, keeping,
storing and/or transitioning of state(s) across connections,
sessions, time and/or operations, for example.
[0101] To address these and other challenges, the present
disclosure provides embodiments of methods and systems for
delivering insights of a virtual session to a network device in a
real-time, scalable and/or extensible manner (e.g., without deep
parsing by a network device). In some embodiments, a separate or
independent VC (sometimes referred to as an App Flow VC) can be
established across or between a client-side agent (e.g., desktop
virtualization client), network device(s) and a server-side agent
(e.g., VDA) for the transmission of insights (e.g., virtualization
session insights). The App Flow VC can be negotiated between these
entities (e.g., between the desktop virtualization client, network
appliances and VDA). The App Flow VC can facilitate scalable and
extensible processing of insights. The App Flow VC can remain
non-interleaved with other VCs in a HDX/ICA stream, and the stream
can be uncompressed to facilitate access to and parsing of the App
Flow VC. Such simple parsing consumes significantly lower levels of
resources, and improves the operation of the network device by
allowing more resources of the network device to perform any other
functions, such as to process a larger number of connections (e.g.,
ICA connections) at a given time. Even if a larger number of
connections is not necessary, lower consumption of CPU resources
for instance results in lower power consumption (e.g., lower energy
wastage to obtain similar insights) and/or heat generation, as
compared with deep parsing. Hence, the present system and methods
allow for substantive improvements in the operation of system
components such as network devices (e.g., SD-WAN and gateway
devices).
[0102] Further, embodiments of the present methods and system can
improve the HDX/ICA platform in addition ways. For example,
embodiments of the present methods and system can provide or
support state transition of App Flow insights or metrics during
network device failover (e.g., high-availability failover), hence
improving operation during such failover. Certain embodiments of
the present methods and system provide or support efficient
identification and prioritization of Multi-stream ICA (MSI) HDX
streams, which reduces resources to access and process data from
such streams. Some embodiments of the present methods and system
provide or support layer 7 (L7, application layer) latency
calculation and communication independent of server processing
time. Some embodiments of the present methods and system provide or
support L7 latency calculation and communication between multiple
network devices. Hence, these solutions can provide metrics that
more accurately characterizes the health and performance of
specific network components, segments or connections.
[0103] In an ICA or HDX configuration for instance, VCs can support
a remote computing experience at a client 102, by providing access
to one or more applications and/or remote desktops hosted on a
server 106. As shown in FIG. 5, VCs can be established using a
server-side agent 504 and a client-side agent 502. As illustrated
in FIG. 5, the system 500 can include a client 102 with a
client-side agent 502 (e.g., Workspace App), a server 106 with a
server-side agent 504 (e.g., VDA), ICA stacks on each of the client
102 and the server 106, that supports the HDX session via a network
link. Each of the ICA stacks 516a-n can include a WinStation driver
(WD) 516a, a protocol driver (PD) 516b, and/or a transport driver
(TD) 516c, each involving one or more corresponding protocols.
[0104] VCs can support communications and functionalities between
the client 102 and the server 106, in provisioning an application
or desktop via remote delivery to the client 102. Virtual channels
can provide a secure way for an application running on the server
106 to communicate with the client 102 or the client-side
environment. Each virtual channel can support communications for
supporting or enabling one or more functionalities of the
application or desktop, such as graphics, disks, COM ports, LPT
ports, printers, audio, video, smart card, and so on, so that these
functionalities are available across the client 102 and the server
106. Some virtual channels can be loaded or established in user
mode 510, and some others can be loaded or established in kernel
mode 512. Virtual channels established in the user mode 510 may
have limited access to the functionalities of the client 102 or the
server 106 (e.g., those allocated to the application for the
virtual channel). Conversely, virtual channels established in the
kernel mode 512 may have full or more expansive access to the
functionalities of the client 102 or the server 106 (e.g., besides
those allocated to the application). A client virtual channel, for
example, can be routed through a WinStation driver 520a (e.g., in
the server-side ICA stack 520a-n), and can be polled or accessed on
the client-side by a corresponding WinStation driver 516a (e.g., in
the client-side ICA stack 516a-n). On the client side, virtual
channels can correspond to virtual drivers each providing a
specific function. The virtual drivers can operate at the
presentation layer protocol level for instance (or another protocol
level). There can be a number of these protocols active at any
given time by multiplexing channels that are provided by for
instance the WinStation protocol layer (or WinStation driver).
Multiple virtual channels can be combined or multiplexed within a
provisioning session (e.g., an ICA/HDX session or traffic
stream).
[0105] Virtual channels can be created by virtualizing one or more
"physical" channels, each virtualized into one or more virtual
channels. For example, several virtual channels may be identified
separately and can carry different types of communications, but may
share the same port corresponding to a physical channel. The use of
virtual channels can allow sharing or data multiplexing on a single
non-virtual channel to support multiple streams of information. One
or more virtual channels may operate to communicate presentation
layer elements from the server 106 to the client device 102. Some
of these virtual channels may communicate commands, function calls
or other messages from the client device 102 to an application or a
remote desktop's operating system. These messages may be used to
control, update or manage the operation and display of the
application or desktop.
[0106] By way of example, a client-side agent 502 may receive, from
a server-side agent 504 via a provisioning (e.g., ICA, RDP, HDX)
session, data associated with a remote desktop environment
generated on a server 106 (e.g., a Citrix Virtual Desktops server).
In some embodiments, the client-side agent 502 may be provided as a
dynamically linked library component for example, that receives
window creation and window process data from the server-side agent
504 for use in displaying a local version of a window generated on
the server 106. In some embodiments, the client-side agent 502 may
receive data such as window attribute data over one or more
connections. The one or more connections may be multiplexed into
one or more virtual channels. Such multiplexing may allow for
different virtual channels to have different bandwidth limits or
different priorities, while still being part of a single transport
layer connection. This can reduce the transport layer overhead
required and provide for SSL or VPN tunnel capability, while still
allowing per-channel compression, buffering, and/or management of
communication priority between the client-side agent 502 and the
server-side agent 504. The virtual channels may be dedicated to
specific content types or purposes. For example, a first
high-priority virtual channel may be dedicated to transmission of
application output data, while a second low-priority virtual
channel may be dedicated to transmission of taskbar thumbnail
images. A plurality of virtual channels can be used for
communicating one or more types of application data (e.g., audio,
graphics, metadata, printer data, disk data, smart card data, and
so on). For instance, some types of application data can each be
conveyed or communication via a dedicated virtual channel within
the provisioning session, and/or certain types of application data
can each be conveyed or communication to the intermediary device by
sharing one or more virtual channels.
[0107] In a HDX session for delivering an application or desktop
(e.g., via Citrix Virtual Apps and Desktops), the protocol exchange
between a client-side agent (e.g., Citrix Workspace App) and a
server-side agent (e.g., Citrix Virtual Apps and Desktops virtual
delivery agent (VDA)) can involve multiple protocols including a
core ICA protocol, and protocols for VCs representing various
technologies, such as graphics, multimedia, printing, drive
mapping, windowing, user input, etc. Deep parsing (e.g.,
decompression, decoding, decryption and/or de-interleaving) of such
virtualization protocols and/or VC data streams can consume
significant processing resources and greatly limit the scalability
of network devices. For instance, network devices (e.g., Citrix
Gateway and SD-WAN) can deeply parse ICA traffic flowing through a
network, having one or more protocols such as transmission control
protocol (TCP) or transport layer security (TLS), enlightened data
transport (EDT) or datagram transport layer security (DTLS) or user
datagram protocol (UDP), common gateway protocol (CGP), ICA
framing, custom ICA encryption (e.g. secure ICA), ICA protocol
itself (e.g., including compression, such as stateful context-based
compression) and de-interleaving of individual core ICA or VC data
streams, and the individual VC protocols in order to gather various
information or insights from a HDX session for instance.
[0108] In addition to HDX, RDP or ICA based sessions, other types
of communications sessions are contemplated that can include
various channels or connections of data streams (e.g., with
features similar to virtual channels), and may involve various
corresponding protocols. Insights, metrics, analytics, statistics
and/or other information (hereafter sometimes generally referred to
as insights) relating to the communication session can be used to
determine and/or improve user experience and the overall health of
the infrastructure of the communications session (e.g., Citrix
Virtual Apps and Desktops infrastructure), and the applications
(e.g., Microsoft Office applications, remote desktop application)
being delivered using the infrastructure. The insights can be
combined with other network-health analysis performed by network
devices, and/or processed and/or used by the network devices (e.g.
Citrix Gateway or Citrix SD-WAN), to for instance adapt or improve
certain operation(s). In addition, such collective insights may be
provided to a management and triaging utility (e.g. Citrix
Director), a management analytics service, or a third-party
collector tool. The collective insights and/or these tools can
allow administrators to view and analyze real-time client, host and
network latency metrics, historical reports and/or end-to-end
performance data, and can allow the administrators to troubleshoot
performance and network issues.
[0109] However, the effort for a network device to deeply parse,
decrypt and/or decompress traffic (e.g., HDX traffic) can hurt or
limit the scalability of the network device and can significantly
increase the cost of supporting (e.g., HDX specific) insights.
These can be memory and CPU intensive operations that directly
affect the number of connections (e.g., ICA connections) that a
network device (e.g., Citrix Gateway or SD-WAN appliance) can
support at a time. Deep parsing of such traffic can be a memory and
CPU intensive operation, mainly because of the stateful
decompression of the ICA stream. "Stateful" can refer to
maintaining, tracking, keeping, storing and/or transitioning of
state(s) across connections, sessions, time and/or operations, for
example.
[0110] In some embodiments, adding additional insights for
retrieval by a network device may entail updating one or more of
the session protocols (e.g., the HDX protocols). Parsing
multi-stream ICA (MSI) streams can further complicate the network
device's parsing mechanism, logic and/or methods. High-availability
(HA) failovers from one network device to another can also be
complicated by the process or requirement of transitioning very
large and complex state between the devices in order to continue
gathering insights. High-availability, for instance, can refer to a
system being tolerant to failure, such as using hardware
redundancy. In some embodiments, measuring the roundtrip latency
between client-side and server-side agents (e.g., Citrix Workspace
App and VDA) can be affected by server load and server processing
time.
[0111] To address these and other challenges, the present
disclosure provides embodiments of methods and systems for
delivering insights of a virtual session to a network device in a
real-time, scalable and/or extensible manner (e.g., without deep
parsing by a network device). In some embodiments, a separate or
independent VC (sometimes referred to as an App Flow VC) can be
established across or between a client-side agent (e.g., desktop
virtualization client), network device(s) and a server-side agent
(e.g., VDA) for the transmission of insights (e.g., virtualization
session insights). The App Flow VC can be negotiated between these
entities (e.g., between the desktop virtualization client, network
appliances and VDA). The App Flow VC can facilitate scalable and
extensible processing of insights.
[0112] Some embodiments of the present methods and systems provide
or support state transition of App Flow insights or metrics during
network device failover (e.g., high-availability failover). Certain
embodiments of the present methods and systems provide or support
efficient identification and prioritization of MSI HDX streams.
Some embodiments of the present methods and systems provide or
support layer 7 (e.g., L7, application layer) latency calculation
and communication independent of host processing time. Some
embodiments of the present methods and systems provide or support
L7 latency calculation and communication between multiple network
devices.
[0113] Referring again to FIG. 5, the system 500 can incorporate an
App Flow VC (e.g., virtual channel 514 or 522) for providing
insights, according to an illustrative embodiment. The App Flow VC
can incorporate one or more features of the VCs discussed above. In
some aspects, the App Flow VC can be identical or similar to other
VCs except that the App Flow VC is configured to carry a different
type of data stream than that carried by the other VCs. The network
link 518, which can include the client 102, server 106 and the ICA
stacks, can communicate a data stream of the App Flow VC. The data
stream can carry insights (e.g., in packets, frames or other
messages) that can be accessed by device(s) in the network link
518.
[0114] The systems and methods of the present disclosure may be
implemented using or involving any type and form of device,
including clients, servers and/or appliances 200 described above
with reference to FIG. 1A-FIG. 1B, FIG. 2 and FIG. 4. As referenced
herein, a "server" may sometimes refer to any device in a
client-server relationship, e.g., an appliance 200 in a handshake
with a client device 102. The server 106 may be an instance,
implementation, or include aspects similar to server 106a-n
described above with reference to at least FIG. 1A. Similarly, the
client 102 may be an instance, implementation, or include aspects
similar to any of the clients 102 a-n described above with
reference to FIG. 1A. The present systems and methods may be
implemented using or involving an intermediary device or gateway,
such as any embodiments or aspects of the appliance or devices 200
described herein. The systems and methods may be implemented in any
type and form of environment, including multi-core devices,
virtualized environments and/or clustered environments as described
herein.
[0115] The server 106 may host one or more applications or
services. Each of the applications or services can include or
correspond to any type or form of application or service. The
application or service may include a network application, a web
application, a Software-as-a-Service (SaaS) application, a
remote-hosted application, and so on. As some non-limiting
examples, an application can include a word processing, spreadsheet
or other application from a suite of applications (e.g., Microsoft
Office360, or Google docs), an application hosted and executing on
a server for remote provisioning to a client, a desktop
application, and/or a HTML5-based application. Packets
corresponding to an application or service 510 may be compressed,
encrypted and/or otherwise processed by the VDA and/or ICA stack
(sometimes referred to as HDX stack, or VDA HDX stack) of the
server 106, and transmitted or delivered to the client 102. The VDA
may include the ICA stack 520a-n (e.g., WD 520a, PD 520b, and TD
520c), and can terminate one end of a VC at the server-side agent
504, with the client-side agent 502 terminating the other end of
the VC.
[0116] In some embodiments, the client 102 may reside at a branch
office or an organization for instance, and may operate within a
client-side network, which may include or correspond to a private
network (e.g., a local area network (LAN) or wide area network
(WAN)). In some embodiments, the server 106 and the client 102 may
be communicably coupled to one another via a private network (e.g.,
a LAN or a software-defined wide area network (SD-WAN)). The server
106 may reside at a server or data center, and may operate within a
server-side network, which may also be a private network (e.g., a
LAN, WAN, etc.).
[0117] One or more network devices can be intermediary between the
client 102 and the server 106. A network device 508 can include or
correspond to any type or form of intermediary device, network
device or appliance, gateway device, middle box device and/or proxy
device, such as but not limited to a NetScaler device, SD-WAN
device, and so on. Each of the server 106, client 102, and network
device(s) in the network link 518 may be communicably coupled in
series.
Negotiation and Establishment of an App Flow VC for Transmission of
Insights
[0118] The server-side agent 504 (e.g., VDA) executing on the
server 106 may initiate establishment of an App Flow VC. The
server-side agent 504 may initiate establishment of an App Flow VC
with a client-side agent 502 (e.g., a desktop virtualization
client) and/or network device(s) in the path between the server 106
and the client 102. All or some of the server-side agent 504, the
client-side agent 502 (e.g., Citrix Workspace App (CWA) or Citrix
Receiver), and the network device(s) (e.g., Citrix Gateway, Citrix
Gateway Service, Citrix SD-WAN) along the network link can choose
to participate in the negotiation of the App Flow VC. These
device(s) can advertise their presence and/or capabilities to
support the App Flow VC.
[0119] For example, the server-side agent's HDX stack can initiate,
establish or otherwise enable the App Flow VC, and can send its
host-to-client (e.g., server 106 to client 102) insights data on a
HDX connection (e.g., using ICA or Common Gateway Protocol (CGP)).
The HDX connection may be the same as a HDX connection for carrying
one or more other VCs (or HDX VCs), except that the App Flow VC
that it carries may be uncompressed and/or non-interleaved with any
other HDX VC(s). This is to facilitate efficient parsing of the App
Flow VC by network device(s) in the network connection. Any of
network device(s) and the client-side agent 502 (e.g., Receiver)
may parse and interpret, or simply ignore the insights data in the
App Flow VC. Within the App Flow VC, insights data may be sent in a
self-descriptive, light-weight extensible format, e.g. in
JavaScript Object Notation (JSON) format.
[0120] Similarly, the client-side agent's HDX stack may establish
or enable the App Flow VC, and send its client-to-host (e.g.,
client 102 to server 106) insights data via the App Flow VC. The
App Flow VC may remain uncompressed and/or non-interleaved with
other HDX VCs to facilitate efficient parsing by network device(s).
The server-side agent 504 (e.g., VDA) may parse and interpret, or
simply ignore the client-to-host insights data in the App Flow
VC.
[0121] In some embodiments, an App Flow protocol capability or data
structure is used to negotiate a configuration (e.g., capabilities)
for the App Flow VC, which can include advertising support for the
App Flow VC by different entities (e.g., along the network link) to
certain entities (e.g., client 102, server 106). The entities can
advertise their support for the App Flow VC by performing
capabilities exchange between the entities. The entities that are
involved in the negotiation can include at least one of the
following: (a) server 106 (host), (b) network device A (e.g.,
gateway), (c) server-side network device B (e.g., SD-WAN device),
(d) client-side network device C (e.g., SD-WAN device), or client
102. The capabilities exchange between the entities can determine a
behavior of App Flow VC for a particular HDX session. More than one
network device (e.g., gateway device, SD-WAN device) may
participate in the negotiation. The capabilities exchange can
include an entity reporting or advertising an App Flow capability
of the entity to one or more entities, or exchanging its App Flow
capability with that of one or more other entities.
[0122] In some embodiments, the App Flow VC capability may include
at least one of the following information or data fields: [0123]
Host (or server) Protocol Version [0124] Host (or server) Flags
[0125] Gateway Protocol Version [0126] Gateway Flags [0127] Host
(or server) side SD-WAN Protocol Version [0128] Host (or server)
side SD-WAN Flags [0129] Client-side SD-WAN Protocol Version [0130]
Client-side SD-WAN Flags [0131] Client Protocol Version [0132]
Client Flags [0133] Session Protocol Version [0134] Session
Protocol Flags
[0135] Referring to FIG. 6, a method 600 of negotiating for and
using an App Flow VC is depicted, in accordance with an
illustrative example. Also depicted in FIG. 6 is a client-side
agent 502, a server-side agent 504, network device(s) 604, and a
management tool or service 602, that interoperate in connection
with the method. As illustrated, various embodiments of the method
can include all or some of a number of operations 1 through 8'.
[0136] Referring to operation 1, the server-side agent 504 (e.g.,
VDA) may report a new App Flow capability in a message (e.g.,
init-request message or packet). If the server 106 does not support
the App Flow VC feature or if the App Flow VC feature is disabled
in the server 106, the App Flow capability of the server-side agent
504 is not sent to the other entities. Otherwise, the server 106
sends the App Flow capability with the server's protocol version
set to the highest version that the server can support. The server
may also set additional flags (e.g., including one or more flags
listed above) identifying granular App Flow features. In some
embodiments, all or some other data fields (e.g., described above)
are initially set to zero (e.g., set to 0 by default, or blanked
out). The App flow capability may be sent in the message (e.g., an
ICA init-request packet) from the server 106 to the client 102.
[0137] Referring to operation 2, a network device 604 can set its
network device (e.g., gateway or SD-WAN) protocol version in the
App Flow capability in the message (e.g., init-request message or
packet). Each network device 604 in the server-to-client path
(e.g., in the network link) may receive or intercept the message
(e.g., init-request packet). The corresponding network device may
parse the App Flow capability in turn along the server-to-client
path, and set the corresponding network device's respective App
Flow protocol version to the highest version it can support. Each
network device 604 may also set additional flags (e.g., including
one or more flags listed above) identifying granular App Flow
features. A protocol version of 0 (e.g., the initial/default value
of 0 remains unchanged or is not set by a corresponding network
device) may indicate that the corresponding network device is not
present in between the server 106 and the client 102 in the network
link. If the corresponding network device residing between the
server 106 and the client 102 does not support the App Flow
protocol or if the App Flow feature is disabled at the
corresponding network device, the capability is left unchanged
(e.g., the protocol version remains zero). All other data fields in
the App Flow capability are left unmodified.
[0138] Referring to operation 3, the client-side agent 502 (e.g.,
Workspace App) may report the capability for the WinStation Driver
at the client-side ICA/HDX stack, in the message (e.g.,
init-response message or packet). If the client 102 does not
support the App Flow feature or the feature is disabled at the
client 102, the capability is not sent back to the host (e.g., the
init-response packet is not transmitted back to the server 106).
The capability is also not sent back to the server 106 if there is
no network device present between the client 102 and the server
106, and/or there is no server-side agent 504 support for the App
Flow VC feature, as indicated by the respective protocol version
data fields being zero (e.g., protocol versions of all possible
network devices are blanked out or set to zero, and/or protocol
version of server 106 is blanked out or set to zero), or lack of
App Flow capability being reported by the server 106. Otherwise,
the client 102 can send back the App Flow capability to the host,
mirroring or maintaining all server and network device data fields
that have already been set. The client 102 can set the client's
protocol version to the highest version it can support. The client
102 may also set additional flags (e.g., including one or more
flags listed above) identifying granular App Flow features. The App
Flow capability may be sent in an ICA init-response packet that is
transmitted from the client 102 to the server 106.
[0139] Referring to operation 4, the client 102 may provide VC-bind
information in the message (e.g., in the init-response for the
WinStation Driver). The VC-bind information may include App Flow VC
in WinStation Driver VC-bind structures. The VC-bind information
may include information associating an identifier of a protocol
(e.g., protocol name of a VC protocol or ICA protocol) for
communicating data using the insights VC, with an identifier of the
insights VC or a component (e.g., WinStation Driver or VC module)
of the client 102 or server 106. The VC-bind information may
include, indicate or identify a protocol name to ID number binding
(sometimes referred to as a protocol name to ID number
association). The protocol name may refer to or identify the core
ICA protocol or a protocol of the App Flow VC. The ID number may
identify or refer to at least one of: an associated VC module, the
App Flow VC, or the WinStation Driver. The client 102 (e.g.,
client-side agent 502, or WinStation Driver) may provide or assign
the protocol name to ID number binding to an App Flow module that
is responsible for implementing the App Flow VC at the client 102.
The VC module can be part of the WinStation Driver, or include the
WinStation Driver, or may be separate from the WinStation Driver.
The VC module can be part of the client-side agent 502 (e.g., VDA),
or include the client-side agent 502, or may be separate from the
client-side agent 502. The client may load the VC module to
implement, initiate and/or establish the App Flow VC at the client
102. The client may send or report the VC-bind information to the
server 106 in the same message (e.g., init-response packet or
message) or another message (e.g., another init-response packet or
message). The VC-bind information may be sent on behalf of the
WinStation Driver responsible for implementing the core ICA
protocol that supports the App Flow VC and/or any other VCs. The
server 106 can receive the VC-bind information (e.g., VC protocol
name to ID number binding), and can use the VC-bind information to
access or otherwise open the App Flow VC and send data on it. The
VC-bind information can be used by any of the network device(s) 604
in the network link 518 to find and parse out the App Flow VC among
other VCs and core protocol.
[0140] Referring to operation 5, the server 106 may commit
capabilities for the App Flow VC and/or the ICA/HDX session. The
server 106 may receive a message (e.g., init-response packet or
message) from the client 102, which can include at least one of:
the App Flow capability or the VC-bind information. The server can
parse, extract, determine and/or analyze the App Flow capability
received from the client 102. For example, the server can detect,
identify or determine the protocol versions and/or additional flags
that might have been set by the client and network device(s) in the
App Flow capability.
[0141] The server 106 can compute or determine a Session protocol
version and/or Session protocol flag(s), for instance using or
according to information set in the App Flow capability. For
example, the Session protocol version may be set to either 0 or the
minimum value of the protocol versions reported by all of the
entities (e.g., server, network device(s), client). The Session
protocol version can be set to 0 if no network device 604 between
the client 102 and the server 106 supports it (e.g., supports the
App Flow VC or feature), or if the client 102 does not support it
(e.g., supports the App Flow VC or feature), or if the App Flow VC
itself is not reported by the client 102 in a protocol name to ID
number binding, and/or if there is neither protocol-level
encryption or custom App Flow VC-level encryption negotiated for
the session. If the value of the Session protocol version is 0,
then no App Flow VC is created or established for the session
(e.g., ICA, RDP or HDX session).
[0142] The server 106 can commit or finalize the Session protocol
version (e.g., if this value is not 0) and/or the Session protocol
flag(s) that are computed or determined. The server 106 can
communicate or propagate the committed Session protocol version
and/or the Session protocol flag(s) to all other entities (e.g.,
network device(s), client) by including these in an App Flow
capability in a message (e.g., an init-connect packet or message)
sent from the server to the client. All or some of these entities
can read the committed Session protocol version and/or Session
protocol flag(s). This process can avoid creating the App Flow VC
and/or sending App Flow data points (e.g., insights) unnecessarily
if no network devices in the network link (between the client 102
and the server 106) is present, interested in or capable of
processing the App Flow insights, and/or if the client-side agent
502 does not support the App Flow feature, and/or if encryption
(e.g., protocol-level encryption, or custom App Flow VC encryption)
is not negotiated or present. For instance, and in some
embodiments, the capability exchange process described herein may
also be used to negotiate custom App Flow VC protocol-level
encryption methods and keys, so that data sent over the App Flow VC
can only be decrypted by a designated network device or the client
(e.g., that has access to the custom App Flow VC protocol-level
encryption methods and keys).
[0143] The server 106 can initiate, establish, create and/or open
the App Flow VC, and can start inserting, writing, providing and/or
sending various insights (e.g., events and data points) into the
App Flow VC. The server 106 can initiate, establish, create and/or
open the App Flow VC, and/or provide the insights, responsive to at
least one of: determining that the Session protocol version is not
0, committing the Session protocol version and/or the Session
protocol flag(s), or sending the committed Session protocol version
and/or the Session protocol flag(s) to the other entities. The
server 106 can open or create the App Flow VC in the session (e.g.,
HDX or ICA session), and can leave the protocol packets of App Flow
VC (and/or other VCs) uncompressed (e.g., in the top level ICA/HDX
protocol), and can leave the protocol packets of App Flow VC
(and/or other VCs) non-interleaved (e.g., to facilitate parsing by
other entities). The App Flow VC data stream can be compressed
(e.g., at the App Flow protocol level). The server 106 can provide
session data (e.g., in JSON format or protocol) from various stack
or VC components, into corresponding VCs, which may be implemented
in user or kernel-mode. The session data can include insights that
are directed into the App Flow VC. The App Flow VC can carry
messages formed and sent in JSON format, to facilitate parsing by
interested entities (e.g., network devices) and/or the client, and
to ensure easy extensibility. For instance, the network devices
(e.g., gateway and/or SD-WAN devices) may be configured to support
and understand the JSON format. However, any other format can be
used, that for instance is supported by the entities and/or can be
efficiently transmitted and processed.
[0144] The App Flow VC can communicate, transmit, carry or convey
one or more App Flow messages (e.g., in JSON or other format). Each
App Flow messages may include at least one of: [0145] Transport
stack connection ID; [0146] HDX Session Globally Unique Identifier
(GUID) (facilitates correlation of each individual data point with
a user and session environment); [0147] Terminal Services Session
ID; [0148] context (additional context to allow other entities to
correlate data points); [0149] timestamp; and [0150] source (e.g.
Virtual Channel or other system component originating the data
point).
[0151] In some embodiments, a message may include or contain at
least one of: (a) Key (Name), (b) Type, or (c) Value. Messages may
be categorized in at least three different groups/types:
[0152] i) Version: Such a message can be a first message (e.g.,
JSON message) sent over the App Flow VC from server to client. Such
a message can denote the JSON protocol version, which may be
different from the App Flow VC protocol version. Such a message can
be used to advertise the set of events and data points implemented
by the server to other entities. Similarly, such a message may be a
first message (e.g., JSON message) sent over the App Flow VC from
client to server, and can be used for a similar purpose.
[0153] ii) Event: Such a message can allow the server to signal the
occurrence of an event on the server. For example, the server may
send an event that signals that "something happened" for a
particular VC in a HDX session, or indicate another system event.
Similarly, such a message can be used by the client to raise events
with other entities.
[0154] iii) Key Value: Such a message can describe an individual
single data point. For example, such a message can describe that a
certain data point has this specific value for a virtual channel in
an HDX session.
[0155] By way of illustration, events can include but is not
limited to one or more of the following: [0156] Application launch,
timestamp [0157] Application termination, timestamp [0158] Process
termination, timestamp [0159] Session disconnection/termination,
timestamp [0160] USB announce device [0161] USB device accepted
[0162] USB device rejected [0163] USB device gone [0164] USB device
reset [0165] USB device reset endpoint
[0166] By way of illustration, data points can include but is not
limited to one or more of the following: [0167] Domain name [0168]
Logon ticket [0169] Server name [0170] Server version [0171]
Session type (e.g., desktop, application) [0172] Client name [0173]
Client version [0174] Client serial number [0175] Application name
[0176] Application module path [0177] Application process ID [0178]
Application launch time [0179] Application termination time [0180]
Session termination time [0181] Launch mechanism [0182] Automatic
reconnection/Session reliability mechanism [0183] ICA Round Trip
Time (RTT) [0184] Layer 7 (L7) latency [0185] VC bandwidth [0186]
Multi-stream ICA (MSI) stream type (primary or secondary)
[0187] Referring to operation 5', the client 102 can read the
session capabilities, can open the App Flow VC, and can write data
into the App Flow VC. The client 102 may read the Session protocol
version and/or Session protocol flag(s) committed by the server
106. According to the instructions (e.g., the committed Session
protocol version and Session protocol flag(s)), the client 102 may
access or open the App Flow VC. Similar to the server 106, the
client 102 may send data points via the App Flow VC in the
client-to-server direction, to be retrieved by one or more network
devices and/or the server 106.
[0188] Referring to operation 6, a network device (e.g., gateway or
SD-WAN device) 604 may read or access the data (e.g., insights)
from the App Flow VC (e.g., data packet or data stream in the App
Flow VC). Each interested or capable network device 604 may read
the Session protocol version and/or Session protocol flag(s)
committed by the server 106. As instructed by the server 106 (e.g.,
via the committed Session protocol version and/or Session protocol
flag(s)), a respective network device 604 may efficiently parse out
(e.g., relative to deep parsing) the App Flow VC among other VCs
and core protocol (e.g., using the VC-bind information), and may
read the insights (e.g., data points) carried in the App Flow VC.
The VC-bind information (e.g., VC protocol name to ID number
association) may be useful to the network device 604 to detect,
identify and/or parse out the App Flow VC among other VC protocols
(e.g., VC-specific or VC-level protocols) and core (or top level
ICA/HDX) protocol. The network device 604 may ignore all other
protocol(s). This can be further facilitated by the fact that the
App Flow VC packets are uncompressed (e.g., at the top level
protocol) and non-interleaved. This can substantially improve the
number of HDX sessions that may be supported by a network device
604 such as a gateway or SD-WAN device. This also improves the user
experience on HDX sessions, since a network device 604 is no longer
a bottleneck for processing (e.g., deep parsing) and throughput.
The network device 604 may decrypt data points (e.g., at the App
Flow VC protocol level) if encryption had been negotiated. (See,
e.g., test results discussed below.)
[0189] Referring to operation 7, the network device 604 can combine
the received App Flow VC data with additional network analytics.
The network device 604 can combine the received App Flow VC data
with additional network analytics generated, accessed and/or
provided by the network device 604, to form or produce combined
insights. The network device 604 can send the combined insights to
a management tool or service 602 (e.g., analytics service) for
further analysis and/or presentation to an administrator. For
example, combined insights may be sent to Citrix Director or Citrix
Management and Analytics System (MAS) or a third-party Insights
tools. Citrix MAS can correspond to or include a centralized
network management and analytics system. From a single platform,
administrators can view, manage network devices, and troubleshoot
network related issues, or issues with specific published desktops
and applications. In some embodiments, the management tool or
service (e.g., MAS) 602 may be configured as an App Flow collector
on a network device (e.g., Citrix Gateway or Citrix SD-WAN) 604,
through which HDX/ICA traffic is flowing. The management tool or
service (e.g., MAS) 602 may receive the records (e.g., combined
insights) from the network device (e.g., Citrix Gateway or Citrix
SD-WAN) 604, analyze the records, and can present them (e.g., in
HDX Insight administrator view). The presented data (e.g., in HDX
Insights administrator view) may help administrators in
troubleshooting issues related to latencies, bandwidth, desktop or
application launch time, desktop or application response time,
etc.
[0190] Referring to operation 8, the client-side agent 502 can read
and can drop (e.g., ignore, remove, discard, filter away) the App
Flow VC data. The client 102 may read some or all data points, and
can drop some or all data points that the client 102 is not
interested in. The client 102 may parse, extract, read and/or
interpret the data points (e.g., provided by the server) from the
App Flow VC. For example, the client 102 may log information about
the App Flow VC data, present information to the end user, respond
back to the server, etc. The client may decrypt data points if
encryption had been negotiated.
[0191] Referring to operation 8', the server-side agent 504 can
read and can drop (e.g., ignore, remove, discard, filter away) App
Flow VC data. Similar to the client 102, the server 106 may read
and/or ignore some or all of the data points sent by the client
102. For instance, the server 106 may parse, extract, read and/or
interpret the data points (e.g., provided by the client 102) from
the App Flow VC. For example, the server 106 may log, present
information to the end user, respond back to the client 102, etc.
The server 106 may decrypt data points if encryption had been
negotiated.
[0192] In some embodiments, the client-side agent 502 (e.g.,
Workspace App) may send some data points on the App Flow VC, which
can be correlated with server-side agent 504 (e.g., VDA) data
points to provide more insights into an HDX Session. In certain
embodiments, the server-side agent 504 (e.g. VDA) may implement,
add or insert data points with session or app-specific details,
e.g. URL's that may be accessed in the session, etc.
[0193] In some embodiments, one or more alternative methods of
implementing the App Flow VC may include: (a) Separating CGP
connections from a network device to the server-side agent (e.g.
VDA); (b) Channeling data from the server-side agent (e.g. VDA) to
the monitoring tool/service (e.g. Director/MAS) over an independent
transport layer connection; (c) Based on uniquely identifying
Connection ID/Session GUID exchanged over HDX protocol, sending
tagged data points from each entity (e.g., client-side agent,
network device, server-side agent) directly to a Cloud Service.
Then the Cloud Service may correlate the data points from the
different sources based on a tag (Connection ID/Session GUID). This
architecture is more appropriate to customers/organizations that
are more willing to accept the use of a Cloud Service as opposed to
on-premises customer/organization owned/controlled network devices
and services.
[0194] Cloud services can be used in accessing resources including
network applications. Cloud services can include an enterprise
mobility technical architecture, which can include an access
gateway in one illustrative embodiment. The architecture can be
used in a bring-your-own-device (BYOD) environment for instance.
The architecture can enable a user of a client device (e.g., a
mobile or other device) to both access enterprise and personal
resources from a client device, and use the client device for
personal use. The user may access such enterprise resources or
enterprise services via a client application executing on the
client device. The user may access such enterprise resources or
enterprise services using a client device that is purchased by the
user or a client device that is provided by the enterprise to user.
The user may utilize the client device for business use only or for
business and personal use. The client device may run an iOS
operating system, and Android operating system, or the like. The
enterprise may choose to implement policies to manage the client
device. The policies may be implemented through a firewall or
gateway in such a way that the client device may be identified,
secured or security verified, and provided selective or full access
to the enterprise resources. The policies may be client device
management policies, mobile application management policies, mobile
data management policies, or some combination of client device,
application, and data management policies. A client device that is
managed through the application of client device management
policies may be referred to as an enrolled device. The client
device management policies can be applied via the client
application for instance.
[0195] In some embodiments, the operating system of the client
device may be separated into a managed partition and an unmanaged
partition. The managed partition may have policies applied to it to
secure the applications running on and data stored in the managed
partition. The applications running on the managed partition may be
secure applications. In other embodiments, all applications may
execute in accordance with a set of one or more policy files
received separate from the application, and which define one or
more security parameters, features, resource restrictions, and/or
other access controls that are enforced by the client device
management system when that application is executing on the device.
By operating in accordance with their respective policy file(s),
each application may be allowed or restricted from communications
with one or more other applications and/or resources, thereby
creating a virtual partition. Thus, as used herein, a partition may
refer to a physically partitioned portion of memory (physical
partition), a logically partitioned portion of memory (logical
partition), and/or a virtual partition created as a result of
enforcement of one or more policies and/or policy files across
multiple apps as described herein (virtual partition). Stated
differently, by enforcing policies on managed apps, those apps may
be restricted to only be able to communicate with other managed
apps and trusted enterprise resources, thereby creating a virtual
partition that is not accessible by unmanaged apps and devices.
[0196] The secure applications may be email applications, web
browsing applications, software-as-a-service (SaaS) access
applications, Windows Application access applications, and the
like. The client application can include a secure application
launcher. The secure applications may be secure native
applications, secure remote applications executed by the secure
application launcher, virtualization applications executed by the
secure application launcher, and the like. The secure native
applications may be wrapped by a secure application wrapper. The
secure application wrapper may include integrated policies that are
executed on the client device when the secure native application is
executed on the device. The secure application wrapper may include
meta-data that points the secure native application running on the
client device to the resources hosted at the enterprise that the
secure native application may require to complete the task
requested upon execution of the secure native application. The
secure remote applications executed by a secure application
launcher may be executed within the secure application launcher
application. The virtualization applications executed by a secure
application launcher may utilize resources on the client device, at
the enterprise resources, and the like. The resources used on the
client device by the virtualization applications executed by a
secure application launcher may include user interaction resources,
processing resources, and the like. The user interaction resources
may be used to collect and transmit keyboard input, mouse input,
camera input, tactile input, audio input, visual input, gesture
input, and the like. The processing resources may be used to
present a user interface, process data received from the enterprise
resources, and the like. The resources used at the enterprise
resources by the virtualization applications executed by a secure
application launcher may include user interface generation
resources, processing resources, and the like. The user interface
generation resources may be used to assemble a user interface,
modify a user interface, refresh a user interface, and the like.
The processing resources may be used to create information, read
information, update information, delete information, and the like.
For example, the virtualization application may record user
interactions associated with a graphical user interface (GUI) and
communicate them to a server application where the server
application may use the user interaction data as an input to the
application operating on the server. In this arrangement, an
enterprise may elect to maintain the application on the server side
as well as data, files, etc., associated with the application.
While an enterprise may elect to "mobilize" some applications in
accordance with the principles herein by securing them for
deployment on the client device (e.g., via the client application),
this arrangement may also be elected for certain applications. For
example, while some applications may be secured for use on the
client device, others might not be prepared or appropriate for
deployment on the client device so the enterprise may elect to
provide the mobile user access to the unprepared applications
through virtualization techniques. As another example, the
enterprise may have large complex applications with large and
complex data sets (e.g., material resource planning applications)
where it would be very difficult, or otherwise undesirable, to
customize the application for the client device so the enterprise
may elect to provide access to the application through
virtualization techniques. As yet another example, the enterprise
may have an application that maintains highly secured data (e.g.,
human resources data, customer data, engineering data) that may be
deemed by the enterprise as too sensitive for even the secured
mobile environment so the enterprise may elect to use
virtualization techniques to permit mobile access to such
applications and data. An enterprise may elect to provide both
fully secured and fully functional applications on the client
device. The enterprise can use a client application, which can
include a virtualization application, to allow access to
applications that are deemed more properly operated on the server
side. In an embodiment, the virtualization application may store
some data, files, etc., on the mobile phone in one of the secure
storage locations. An enterprise, for example, may elect to allow
certain information to be stored on the phone while not permitting
other information.
[0197] In connection with the virtualization application, as
described herein, the client device may have a virtualization
application that is designed to present GUIs and then record user
interactions with the GUI. The virtualization application may
communicate the user interactions to the server side to be used by
the server-side application as user interactions with the
application. In response, the application on the server-side may
transmit back to the client device a new GUI. For example, the new
GUI may be a static page, a dynamic page, an animation, or the
like, thereby providing access to remotely located resources.
[0198] The client device may use cloud services to connect to
enterprise resources and enterprise services at an enterprise, to
the public Internet, and the like. The client device may connect to
enterprise resources and enterprise services through virtual
private network connections. The virtual private network
connections, also referred to as microVPN or application-specific
VPN, may be specific to particular applications (e.g., as
illustrated by microVPNs), particular devices, particular secured
areas on the client device (e.g., as illustrated by O/S VPN), and
the like. For example, each of the wrapped applications in the
secured area of the phone may access enterprise resources through
an application specific VPN such that access to the VPN would be
granted based on attributes associated with the application,
possibly in conjunction with user or device attribute information.
The virtual private network connections may carry Microsoft
Exchange traffic, Microsoft Active Directory traffic, HyperText
Transfer Protocol (HTTP) traffic, HyperText Transfer Protocol
Secure (HTTPS) traffic, application management traffic, and the
like. The virtual private network connections may support and
enable single-sign-on authentication processes. The single-sign-on
processes may allow a user to provide a single set of
authentication credentials, which are then verified by an
authentication service. The authentication service may then grant
to the user access to multiple enterprise resources, without
requiring the user to provide authentication credentials to each
individual enterprise resource.
[0199] The virtual private network connections may be established
and managed by an access gateway. The access gateway may include
performance enhancement features that manage, accelerate, and
improve the delivery of enterprise resources to the client device.
The access gateway may also re-route traffic from the client device
to the public Internet, enabling the client device to access
publicly available and unsecured applications that run on the
public Internet. The client device may connect to the access
gateway via a transport network. The transport network may use one
or more transport protocols and may be a wired network, wireless
network, cloud network, local area network, metropolitan area
network, wide area network, public network, private network, and
the like.
[0200] The enterprise resources may include email servers, file
sharing servers, SaaS/Web applications, Web application servers,
Windows application servers, and the like. Email servers may
include Exchange servers, Lotus Notes servers, and the like. File
sharing servers may include ShareFile servers, and the like. SaaS
applications may include Salesforce, and the like. Windows
application servers may include any application server that is
built to provide applications that are intended to run on a local
Windows operating system, and the like. The enterprise resources
may be premise-based resources, cloud based resources, and the
like. The enterprise resources may be accessed by the client device
directly or through the access gateway. The enterprise resources
may be accessed by the client device via a transport network. The
transport network may be a wired network, wireless network, cloud
network, local area network, metropolitan area network, wide area
network, public network, private network, and the like.
[0201] Cloud services can include an access gateway and/or
enterprise services. The enterprise services may include
authentication services, threat detection services, device manager
services, file sharing services, policy manager services, social
integration services, application controller services, and the
like. Authentication services may include user authentication
services, device authentication services, application
authentication services, data authentication services and the like.
Authentication services may use certificates. The certificates may
be stored on the client device, by the enterprise resources, and
the like. The certificates stored on the client device may be
stored in an encrypted location on the client device, the
certificate may be temporarily stored on the client device for use
at the time of authentication, and the like. Threat detection
services may include intrusion detection services, unauthorized
access attempt detection services, and the like. Unauthorized
access attempt detection services may include unauthorized attempts
to access devices, applications, data, and the like. Device
management services may include configuration, provisioning,
security, support, monitoring, reporting, and decommissioning
services. File sharing services may include file management
services, file storage services, file collaboration services, and
the like. Policy manager services may include device policy manager
services, application policy manager services, data policy manager
services, and the like. Social integration services may include
contact integration services, collaboration services, integration
with social networks such as Facebook, Twitter, and LinkedIn, and
the like. Application controller services may include management
services, provisioning services, deployment services, assignment
services, revocation services, wrapping services, and the like.
[0202] The enterprise mobility technical architecture of cloud
services may include an application store. The application store
may include unwrapped applications, pre-wrapped applications, and
the like. Applications may be populated in the application store
from the application controller. The application store may be
accessed by the client device through the access gateway, through
the public Internet, or the like. The application store may be
provided with an intuitive and easy to use User Interface.
[0203] Referring to FIG. 7, an example system that illustrates an
implementation of App Flow 700 data points collection and
transmission at a server (or server-side agent or VDA) is depicted.
The system can include a client-side agent 502 (e.g., Citrix
Workspace App or Receiver), a server-side agent 504 (e.g., Citrix
Virtual Apps and Desktops VDA), and a network device 604 (e.g., a
NetScaler device). In connection with FIG. 7 for instance,
NetScaler App Flow (NSAP) is sometimes also referred to as App
Flow. Citrix NetScaler (or NetScaler) is referenced here by way of
example, and can also be replaced with any type or form of network
device. VDA is referenced here by way of example, and can also be
replaced with any type or form of server-side agent 504. Likewise,
Citrix Workspace App (or Receiver) is referenced here by way of
example, and can also be replaced with any type or form of
client-side agent 502. The following is an example process flow,
and can include some or all of the following operations:
[0204] At operation 705, after the VDA boots, the NSAP service on
the VDA can instantiate an Event Tracing for Windows (ETW)
Controller and can start an ETW live session. At operation 710, the
Citrix Workspace App can start an ICA session and a new NSAP driver
can initiate the NSAP VC from the Receiver endpoint. The NSAP
driver may discard all data coming on this NSAP VC, or it can use
the statistics received. At operation 715a and 715b, user mode HDX
components on the VDA can use the NSAP SDK (NsapSetxxx) to send
data points to Citrix Netscaler App Experience Service (CtxNsapSvc)
717. At operation 720, Kernel mode HDX components on the VDA can
use the NSAP SDK (NsapSetxxx) to send data points to CtxNsapSvc. At
operation 725, a CtxNsap provider library can send ETW events to
the NSAP ETW Consumer 727 hosted by CtxNsapSvc. At operation 730,
the NSAP Service can encapsulate the data points (e.g., into a JSON
format) and can send it to the NSAP virtual channel (or App Flow
VC). At operation 735, network device 604 (e.g., NetScaler) can
intercept the NSAP VC message and can extract the required data. At
operation 740, the message can further be transmitted to the Citrix
Workspace App along with all other HDX traffic. At operation 745,
the Receiver NSAP VC driver may discard the NSAP VC message. In
testing mode, the NSAP VC driver may parse the content and can
display it in DebugView or in a file for test automation purposes.
The NSAP VC driver may also interpret the data in non-testing
mode.
[0205] Referring to FIGS. 8-10, illustrative test results are
provided including those from an implementation using an App Flow
VC. The session bandwidth (BW) in each of FIGS. 8 and 9 can refer
to HDX traffic load. FIG. 8 depicts a graph 800 of example test
results on number of ICA/HDX sessions for a session bandwidth of
125 Kbps (e.g., typical workload). The test results, from left to
right, show the case where no insights were parsed (when no App
Flow VC is implemented), the case where deep-parsing is performed
(when no App Flow VC is implemented), and the case where App Flow
VC is implemented for efficient parsing. FIG. 9 depicts a graph 900
of example test results on number of ICA/HDX sessions for a session
bandwidth of 400 Kbps (e.g., graphics rich workload). The test
results, from left to right, show the case where no insights were
parsed (when no App Flow VC is implemented), the case where
deep-parsing is performed (when no App Flow VC is implemented), and
the case where App Flow VC is implemented for efficient parsing.
For each session bandwidth, the number of HDX sessions that can be
served is about 2.5.times. higher with the App Flow VC based
implementation, as compared with the deep parsing implementation.
The actual difference is likely to be higher because of certain
bottlenecks in the test setup. As discussed earlier, deep parsing
is computationally and resource intensive, which reduces the number
of HDX sessions that can be served. Even when the App Flow VC is
used (and some computational resource is consumed for a more
efficient parsing), the number of HDX sessions that can be served
appear to be similar to the case where no insights were parsed.
[0206] FIG. 10 depicts a graph 1000 of example test results on
network device CPU usage (e.g., Gateway appliance packet engine CPU
usage). The test results show the case where no insights were
parsed (when no App Flow VC is implemented), the case where
deep-parsing is performed (when no App Flow VC is implemented), and
the case where App Flow VC is implemented for efficient parsing.
The CPU usage is shown under the condition that the number of
sessions are maxed out. Sessions are considered maxed out when
outgoing bandwidth goes down by 10% and user experience (UX)
becomes sluggish. The test results show that when App Flow VC is
used (and some computational resource is consumed for a more
efficient parsing), the level of CPU usage (about 23%) is only
slightly higher than that for case where no insights were parsed
(about 15%). Hence, CPU usage under the App Flow VC based
implementation is fairly low even when number of sessions are maxed
out. However, in the case where deep-parsing is performed, the CPU
usage (which is near 100%) is much higher than both of the other
cases.
[0207] Referring now to FIG. 11, depicted is a flow diagram of a
method 1100 of establishing independent application flow virtual
channels. The method 1100 may be performed or implemented using any
of the components detailed herein, for example, the client 102, the
server 106, the appliance 200, the network link 518, or the network
device 604, among others. In brief overview, a first computing
device may send a request message for virtual channels (1105). The
first computing device may receive a response message indicating
capabilities (1110). The first computing device may determine
capabilities in supporting virtual channels (1115). The first
computing device may establish virtual channels (1120). The first
computing device may identify insights from virtual channel
(1125).
[0208] In further detail, a first computing device (e.g., the
client 102 or the server 106) may send a request message for
virtual channels (e.g., virtual channels 506a-n or 508a-n) (1105).
The request message may be transmitted, provided, or otherwise sent
by the first computing device to a second computing device (e.g.,
the client 102 or the server 106), and may be communicated via an
intermediary device (e.g., a network device 604 in the network link
518). The request message may be a request to setup or establish at
least one virtual channel for an application flow feature (also
referred to as an insights virtual channel) of the first computing
device or the second computing device, or the intermediary device.
The first computing device may generate the request message to
indicate one or more capabilities of the first computing device
(and/or to request one or more capabilities of other devices) to
support an insights virtual channel between the first computing
device and the second computing device. The capabilities may
indicate compatibility of the first computing device in supporting
an insights virtual channel, and may indicate types of insights
data transferrable via the virtual channel. In some embodiments,
the capabilities may include one or more protocol versions
supportable by the first computing device in using at least one of
the virtual channels to support insights. For example, the request
message can indicate the highest version or most recent version of
the protocol supported by the first computing device in accordance
to which the insights are to be provided via the virtual
channel.
[0209] The first computing device may receive a response message
indicating capabilities (1110). The response message may be
identified, obtained, or received by the first computing device
from the second computing device, and may be communicated via the
network device (e.g., through the network link 518). Upon receipt
of the request message from the first computing device, the second
computing device may generate the response message to include the
one or more capabilities of the second computing device to support
an insights virtual channel between the first computing device and
the second computing device. The capabilities may indicate
compatibility of the second computing device in supporting an
insights virtual channel, and may indicate types of insights data
transferrable via the virtual channel. In some embodiments, the
capabilities may include one or more protocol versions supportable
by the second computing device in using at least one of the virtual
channels to support insights.
[0210] In some embodiments, the second computing device may
generate the response message to include information for
establishing the virtual channel to support insights. The
information may include: an identifier of a protocol (e.g.,
protocol type, protocol name, or ICA protocol) in accordance to
which data is to be communicated via the insights virtual channel,
an identifier of the virtual channel itself to be used as the
insights virtual channel, and a component (e.g., WinStation, VC
module, or other application or communication interface) of the
first computing device to use the insights virtual channel, among
others. The information may also include an association between the
identifier of the protocol and the identifier of the virtual
channel, or an association between the identifier of the protocol
and the component of the first computing device (e.g., VC bind
information). With the generation of the response message, the
second computing device may transmit the response message to the
first computing device.
[0211] When transmitted from the second computing device, the
intermediary device may identify, intercept, or otherwise receive
the request message. Upon receipt or interception, the intermediary
device may insert the one or more capabilities of the intermediary
device to support the insights virtual channel between the first
computing device and the second computing device via the
intermediary device. The capabilities may indicate compatibility of
the intermediary device in supporting an insights virtual channel,
and may indicate types of insights data transferrable via the
virtual channel between the first computing device and the second
computing device. In some embodiments, the capabilities may include
one or more protocol versions supportable by the intermediary
device in using at least one of the virtual channels to support
insights. In some embodiments, the intermediary device may include
or insert information for establishing the virtual channel to
support insights. The information inserted by the intermediary
device may be the same as described above with respect to the
second computing device. With the insertion of the capabilities or
information, the intermediary device may forward or otherwise send
the response message to the first computing device.
[0212] The first computing device may determine capabilities in
supporting virtual channels (1115). Upon receipt of the response
message, the first computing device may parse the response message
to identify the capabilities of the second computing device and the
network device in supporting an insights virtual channel. By
parsing the response message, the first computing device may
determine the capabilities in supporting the insights virtual
channel. From the response message, the first computing device may
identify the one or more protocol versions supported by the second
computing device and the intermediary device. Based on the
identification, the first computing device may find, identify, or
determine at least one protocol version for the insights virtual
channel supported by the first computing device, the second
computing device, and the intermediary device. For example, the
first computing device may determine the highest or most recent
protocol version supported by all three devices. In addition, the
first computing device may identify the information for
establishing the insights virtual channel from the response
message, such as the association between the identifier of the
protocol and the identifier of the virtual channel or the
association between the identifier of the protocol and the
component of the first computing device (e.g., VC bind
information).
[0213] The first computing device may establish virtual channels
(1120). A set of virtual channels may be established between the
first computing device and the second computing device via the
intermediary device. In some embodiments, the virtual channels in
the set may be interleaved with each other to carry data between
the first computing device and the second computing device. The
data carried via the virtual channels may be compressed. Separately
from the set of virtual channels, the first computing device may
initiate, setup, or otherwise establish an insights virtual
channel. The insights virtual channel may be separate from (e.g.,
not interleaved with) the other virtual channels between the first
computing device and the second computing device. The insights
virtual channel may carry uncompressed data relating to analytics
regarding the communications between the first computing device and
the second computing device via the intermediary device. The
insights virtual channel may be used by one or more of the three
devices, such as the first computing device, the second computing
device, and the third computing device (e.g., an intermediary
device or network device 604 in the network link 518).
[0214] The establishment of the insights virtual channel may be in
accordance with the capabilities the first computing device, the
second computing device, and the intermediary device. In some
embodiments, the first computing device may use at least one
protocol version identified as supported by the first computing
device, the second computing device, and the intermediary device to
establish the insights virtual channel. For example, the first
computing device may use the highest or most recent protocol
version determined to be supported by all three devices to
establish the insights virtual channel. In some embodiments, the
first computing device may generate and send the information on
establishment of the insights virtual channel to the second
computing device and the intermediary device. The information may
have been lacking in the response message from the second computing
device or the intermediary device, and may be generated by the
first computing device. The information may include, for example,
the association between the identifier of the protocol and the
identifier of the virtual channel or the association between the
identifier of the protocol and the component of the first computing
device (e.g., VC bind information). Once generated, the first
computing device may send the information via one of the set of
virtual channels previously established between the first computing
device and the second computing device.
[0215] The first computing device may identify insights from the
insights virtual channel (1125). With the establishment of the
insights virtual channel, the first computing device may exchange
analytics data (sometimes referred herein as insights or metrics)
regarding the first computing device, the second computing device,
any other device(s), and/or the communication between the first
computing device and the second computing device via the network
link of the intermediary device. The analytics data may include
events and data points, e.g., regarding the communication session
as described herein above. The analytics data may be uncompressed
and may be non-interleaved with other data, and may be lacking in
the other set of virtual channels established between the first
computing device and the second computing device. To access, the
first computing device may identify the insights virtual channel
from the virtual channels using the setup information. The
information may include, for example, an identifier of the
protocol, an identifier of the virtual channel, or the component of
the first computing device to use the insights virtual channel,
among others, or any association there between. Once the insights
virtual channel is identified, the first computing device may
retrieve, identify, or otherwise access the analytics data (e.g.,
from the second computing device or the intermediary device). In
some embodiments, the first computing device may request, fetch, or
otherwise retrieve the analytics data from the second computing
device or the intermediary device. In some embodiments, upon
establishment of the insights virtual channel, the first computing
device, the second computing device, and the intermediary device
all may commence exchanging or sharing analytics data via the
insights virtual channel. Using the analytics data, the first
computing device, the second computing device, or the intermediary
device may re-configure, adjust, or set the data exchanged or
shared via the other virtual channels.
State Transition of App Flow Metrics During Network Appliance
Failover (High-Availability)
[0216] Referring now to FIG. 12, depicted is a block diagram of a
system 1200 for transitioning application flow metrics during
appliance failover. The system 1200 may include one or more
components detailed herein in conjunction with FIGS. 5-11, such as
the client 102, the client-side agent 502, one or more network
devices 604a and 604b (sometimes referred herein as a gateway or an
intermediary device), at least one virtual channel 506 and 508, a
server-side agent 504, and a server 106. In overview, a virtual
channel (e.g., an insights virtual channel) may be rerouted or
redirected from one network device 604b to another network device
604a. For instance, one of the network devices 604a or 604b
(hereinafter generally referred to as network device 604) may
determine whether to re-route a virtual channel from itself to
another network device 604. In some embodiments, a client 102 or
server 106 may detect a failure or failover situation associated
with a first network device 604b, and may determine whether to
re-route a virtual channel through the first network device 604b to
another network device 604a. The virtual channel 506 and 508 may
have been established between the client 102 and server 106 through
the network device 604. The re-routing may be performed in response
to a network (application) failover. In response to the
determination, the network device 604 may identify or receive a
protocol state of the virtual channel. The protocol state may
include information regarding the establishment of the virtual
channel, such as an association between the protocol identifier
with the identifier of the virtual channel or between the protocol
identifier with a component of the client 102 or server 106 (e.g.,
WinStation, VC module, or another application). Using the protocol
state, the network device 604 may access the insights exchanged
across the insights virtual channel 506 or 508. The insights may be
from the client 102, the server 106 or another network device, and
may be communicated through the network device 604.
State Transition Via Shared State
[0217] In some embodiments, and by way of a non-limiting example, a
network device (e.g., the network device 604 of system 1200) may be
load-balanced, e.g., a Gateway may be load-balanced between Gateway
instance 1 (e.g., network device 604b) and Gateway instance 2
(e.g., network device 604a). A specific HDX session may be
initially established from client 1 via Gateway 1 to VDA host 1. An
App Flow VC may have been established and data points may have been
transmitted. ICA protocol-level encryption may have been negotiated
and used, e.g., Basic or Secure ICA encryption. App Flow
VC-specific protocol-level encryption may have been negotiated and
used. A failure of Gateway 1 (e.g., network device 604b) may cause
the connection to be re-routed via Gateway 2 (e.g., network device
604a). In another scenario, a network disruption may cause client 1
to re-establish transport level connection, which in turn may
re-route the connection via Gateway 2, even without any failure at
Gateway 1. In both of these cases, the client 1 can reconnect to
the host HDX session (e.g., using standard CGP Session Reliability
mechanism).
[0218] In transitioning the App Flow state from Gateway 1 to
Gateway 2, there can be a problem with continuing to re-interpret
the protocol traffic, including decrypting ICA protocol-level
encryption and/or App Flow protocol-level encryption, and
identifying App Flow VC messages. Protocol state maintained by
Gateway 1 can be continuously saved in shared storage, or at a
globally available service, or a Remote Dictionary Server (Redis),
etc. The protocol state may include, but is not limited to any one
or more of the following: (a) App Flow VC negotiated capabilities:
Session protocol version and flags, protocol version and flags for
each entity; (b) App Flow VC protocol name to ID number
association/binding; (c) Recorded App Flow VC version, events, data
points; (d) Encryption method, keys, last encrypted byte at ICA
protocol-level; and/or (e) Encryption method, keys, last encrypted
byte at App Flow VC protocol-level.
[0219] Gateway 2 may retrieve and restore the shared protocol state
from shared storage, identified by protocol-level identifier such
as CGP cookie, Session GUID, etc. To continue parsing App Flow VC
messages, Gateway 2 may for example perform any one or more of the
following: (a) Re-synchronize transmitted and received packets at
CGP-level; (b) Use last encrypted byte (at ICA protocol-level) to
continue to decrypt ICA traffic and maintain encryption state; (c)
Optionally, for optimization, use flags in CGP protocol to indicate
presence of self-contained App Flow VC message; (d) If Gateway 2
can support the same Session capabilities as the already negotiated
ones by Gateway 1: use last encrypted byte (at App Flow VC
protocol-level) to continue to decrypt App Flow VC messages and
maintain encryption state. Otherwise: Do not support App Flow VC;
or clear protocol state and trigger re-negotiation of App Flow VC
protocol capabilities as previously described. This may cause delay
in processing but can ensure that App Flow functionality is still
supported. Thus, the App Flow state can be successful transitioned
from Gateway 1 to Gateway 2, and Gateway 2 can continue to receive
and interpret new events and data points.
[0220] State Transition Via In-Line State Re-Initialization
[0221] In some scenarios, the protocol state may not be easily,
efficiently or quickly shared between different Gateway instances
(e.g., the network devices 604 of system 1200). For example, for
purposes of high-availability and resiliency, redundant Gateway
instances may reside on different cloud platforms, e.g., Microsoft
Azure or Amazon AWS. For additional resiliency a redundant Gateway
instance may exist in a co-location facility or on-premises.
Therefore, as an alternative, the App Flow channel (or VC) may be
designed as stateless or, rather, during failover the new Gateway
instance may be re-initialized (or re-seeded) with sufficient state
to continue parsing the App Flow data, where the re-initialization
may be performed in-line via a tunneling protocol, e.g. CGP, or via
the App Flow VC itself, or a combination. By way of a non-limiting
example, the in-line state re-initialization process may occur as
illustrated below:
[0222] A network device may be load-balanced, e.g., a Gateway may
be load-balanced between Gateway instance 1 and Gateway instance 2.
A specific HDX session may be initially established from client 1
via Gateway 1 to VDA host 1. An App Flow VC may have been
established and data points may have been transmitted. As a result
of determining that strong network-level encryption, e.g. with TLS
or DTLS existing end-to-end, ICA protocol-level encryption, e.g.,
Basic or Secure ICA encryption, may be turned off. App Flow
VC-specific protocol-level encryption may have been negotiated and
used. A failure of Gateway 1 may cause the connection to be
re-routed via Gateway 2. In another scenario, a network disruption
may have caused client 1 to re-establish transport, which in turn
might have re-routed the connection via Gateway 2, even without any
failure at Gateway 1. In both of these cases, the client could use
the standard CGP Session Reliability mechanism to reconnect to the
host HDX session.
[0223] When transitioning the App Flow state from Gateway 1 to
Gateway 2, there can be a problem with continuing to re-interpret
the protocol traffic, including App Flow protocol-level encryption,
and identifying App Flow VC messages. In some embodiments, upon CGP
reconnect, new CGP capability is exchanged. In client-to-host
and/or host-to-client direction, the CGP capability carries
sufficient data to allow Gateway 2 to identify the App Flow VC.
This data can include the App Flow VC protocol name to ID number
association/binding. Also upon CGP reconnect, the client and host
can issue an event to their App Flow VC modules, which can instruct
the App Flow VC itself to for instance (re)send one or more of the
following: [1] App Flow VC negotiated capabilities: Session
protocol version and flags, protocol version and flags for each
entity (Unencrypted. First data point sent); [2] Encryption method,
keys, last encrypted byte at App Flow VC protocol-level
(Unencrypted); [3] App Flow VC JSON protocol version; [4] Session
GUID; [5] Additional data points may also be sent reflecting
current HDX session state; and so on. The bulk of historical data
points that do not require real-time synchronization could still be
stored in a globally reachable or replicated MAS.
[0224] To continue parsing App Flow VC messages, Gateway 2 may for
example perform one or more of the following: (a) Re-synchronize
transmitted and received packets at CGP-level; (b) Optionally, for
optimization, use flags in CGP protocol to indicate presence of
self-contained App Flow VC message; (c) Use the App Flow VC
protocol name to ID number association/binding to start parsing the
App Flow VC; (d) If Gateway 2 can support the same Session
capabilities as the already negotiated ones by Gateway 1 (which can
be a reasonable assumption for Cloud instances where capabilities
can be kept uniform): i) Queue all App Flow VC packets, e.g. those
previously CGP-buffered by client and/or host and now
re-synchronized by CGP, until packets with unencrypted data points
[1] and [2] above are received, ii) Use last encrypted byte (at App
Flow VC protocol-level) to continue to decrypt App Flow VC messages
and maintain encryption state, and iii) Interpret and flush the
previously CGP-buffered data points, if any; (e) Otherwise (if
Gateway 2 cannot support the same Session capabilities as the
already negotiated ones by Gateway 1): i) Do not support App Flow
VC, or ii) clear protocol state and trigger re-negotiation of App
Flow VC protocol capabilities as previously described. This may
cause delay in processing but can ensure that App Flow
functionality is still supported. Thus, the App Flow state can be
successful transitioned from Gateway 1 to Gateway 2, and Gateway 2
continues to receive and interpret new events and data points.
State Transitions During Appliance Failover
[0225] Referring now to FIG. 13, depicted is a flow diagram of a
method 1300 of transitioning application flow metrics during
appliance failover. The method 1300 may be performed or implemented
using any of the components detailed herein, for example, the
client 102, the server 106, the appliance 200, or the network
device 604 (or network device 604a or 604b of system 1200), among
others. The method 1300 can include the functionalities described
herein, such as state transition via shared state and state
transition via in-line state re-initialization. In brief overview,
a first intermediary device may determine whether a virtual channel
is re-routed (1305). If not re-routed, the first intermediary
device may monitor the virtual channels (1310). If re-routed, the
first intermediary device may receive a protocol state (1315). The
first intermediary device may identify information and capabilities
from the protocol state (1320). The first intermediary device may
perform a state transition (1325). The first intermediary device
may access insights communicated via a virtual channel (1330).
[0226] In further detail, a first intermediary device (e.g., the
network device 604b) may determine whether an insights virtual
channel (e.g., virtual channel 506 or 508) (1305) is re-routed. The
insights virtual channel may be established between a first
computing device (e.g., the client 102 or the server 106) and a
second computing device (e.g., the client 102 or the server 106).
Furthermore, the insights virtual channel may have been initially
established through a second intermediary device (e.g., the network
device 604b) between the first computing device and the second
computing device. The insights virtual channel may be re-routed
from the second intermediary device to the first intermediary
device in response to a failure at or associated with the second
intermediary device. The failure causing the re-routing may
include, for example, a network disruption causing interruption of
the insights virtual channel, disabling of the second intermediary
device, or any other event leading to the second intermediary
device being unable or unsuitable to handle or carry the insights
virtual channel between the first and second computing device. To
determine whether the insights virtual channel is to be re-routed,
the first intermediary device may monitor the insights virtual
channel for one or more failures at or associated with the second
intermediary device. Upon detection of the failure, the first
intermediary device may determine that the insights virtual channel
is to be re-routed. Otherwise, if the insights virtual channel is
determined to be maintained or not re-routed, the first
intermediary device may monitor the virtual channels (1310). The
first intermediary device may continue to monitor for re-routing of
the insights virtual channel from another device (e.g., the second
intermediary device or another network device 604) to the first
intermediary device, and may repeat the functionality of
(1305).
[0227] If the insights virtual channel is determined to be
re-routed, the first intermediary device may receive a protocol
state (1315). The first intermediary device may access, retrieve,
or otherwise access the protocol state of the insights virtual
channel re-routed from the second intermediary device to the first
intermediary device. The protocol state may be used to re-configure
the insights virtual channel upon re-routing from one intermediary
device to another intermediary device. In some embodiments, the
first intermediary device may retrieve, identify, or otherwise
receive the protocol state from the first computing device or the
second computing device, between which the insights virtual channel
was established. The protocol state may be received from a
component (e.g., App Flow VC module, WinStation, or other
application) of the first computing device or the second computing
device.
[0228] In some embodiments, the first computing device may identify
the protocol state from another source, besides the first computing
device, the second computing device, or the second intermediary
device. The protocol state for the insights virtual channel may be
stored and maintained on a shared storage (e.g., a database in the
network link 518). The shared storage may be accessible by one or
more intermediary devices. For example, when the second
intermediary device established the insights virtual channel
between the first and the second computing devices, the second
intermediary device may have stored the protocol state for the
insights virtual channel onto the shared storage. The first
intermediary device may access the storage to retrieve, obtain, or
otherwise identify the protocol state maintained thereon.
[0229] In some embodiments, the first intermediary device may use a
protocol-level identifier to identify the protocol state. The
protocol-level identifier may describe the communications through
the insights virtual channel, such as a cookie or a session
identifier. The first intermediary device may identify the
protocol-level identifier from the insights virtual channel (e.g.,
based on the communications) to be re-routed from the second to the
first intermediary device. The first intermediary device may also
identify the protocol-level identifier from the shared storage
accessible by one or more of the intermediary devices. With the
identification, the first intermediary device may find or identify
the protocol state of the insights virtual channel being re-routed
in the shared database.
[0230] The first intermediary device may identify information and
capabilities from the protocol state (1320). From the protocol
state for the insights virtual channel, the first intermediary
device may extract, obtain, or otherwise identify the information
or capabilities, among other data. The protocol state may include
information and capabilities in relation to the insights virtual
channel. The first intermediary device may identify the information
included in the protocol state. The information of the protocol
state may be for the establishment or re-establishment of the
insights virtual channel between the first computing device and the
second computing device. The information may include: an identifier
of a protocol (e.g., protocol type, protocol name, or ICA protocol)
in accordance to which data is to be communicated via the insights
virtual channel, an identifier of the virtual channel itself to be
used as the insights virtual channel, and a component (e.g.,
WinStation driver, VC module, or other application or communication
interface) of the first or the second computing device to use the
insights virtual channel, among others. The information may also
include an association between the identifier of the protocol and
the identifier of the virtual channel or an association between the
identifier of the protocol and the component of the first computing
device (e.g., VC bind information), among others.
[0231] The first intermediary device may determine or identify the
capabilities included in the protocol state. The capabilities may
indicate the compatibility common among the first computing device,
the second computing device, and the second intermediary device in
supporting communications of analytics data across the insights
virtual channel. The capabilities of the protocol state may be
negotiated across the first computing device, the second computing
devices, and one of the intermediary devices (e.g., the second
intermediary device) to support communicating analytics data via
the insights virtual channel. The insights virtual channel
initially routed through the second intermediary device may be
establish in accordance with negotiations across the first
computing device, the second computing device, and the second
intermediary device. The negotiations may include identifying the
highest or most recent protocol version in accordance to which to
setup the insights virtual channel in communicating the insights.
The capabilities identified from the protocol state may include one
or more protocol versions supportable by the first computing
device, the second computing device, and the second intermediary
device in using at least one of the virtual channels to support
insights.
[0232] In some embodiments, the first intermediary device may
identify or determine other data included in the protocol state.
The protocol state for the insights virtual channel may also
include data regarding the insights virtual channel itself or
communications through the insights virtual channel, such as a
protocol name, information about one or more events, and data
points, among others. The protocol name may define or include an
identifier corresponding to a type of protocol used to establish
the insights virtual channel (e.g., ICA protocol). The information
on the events may correspond to a function or an action by the
first computing device or the second computing device, such as by
an application or process running thereon. The data points may
define or describe one or more events of one or more of the
computing device(s) and the intermediary device(s), that can be
communicated across the insights virtual channel. The protocol
state for the insights virtual channel may also include data
defining or supporting encryption of the communications across the
insight virtual channel, such as an encryption method, an
encryption key, and one of the encrypted bytes, among others. The
encryption method may define a cryptographic technique or protocol
used to encrypt or obfuscate the analytics data (e.g., the events
and data points). The encryption key may define a transformation
applied by the encryption method in obfuscating the analytics data.
The encrypted byte may correspond to a chunk of the analytics data
(in byte size) exchanged via the insights virtual channel. In some
embodiments, the encrypted byte referred to in the protocol state
may correspond to the last encrypted byte transmitted across the
insights virtual channel prior to re-routing from the second
intermediary device to the first intermediary device.
[0233] The first intermediary device may perform a state transition
(1325). In re-routing the insights virtual channel from the second
intermediary device, the first intermediary device may perform the
state transition in accordance with a shared state or in-line state
re-initialization technique as detailed herein. In some
embodiments, the first intermediary device may re-synchronize
packets transmitted or received via the insights virtual channel at
a common gateway protocol level in performing the state transition.
The common gateway protocol level may be defined by or may
correspond to the protocol-level identifier. Using the gateway
protocol level, the first intermediary device may determine a
proper sequence of packets to synchronize the packets exchanged
across the insights virtual channel. In some embodiments, the first
intermediary device may initialize or re-initialize itself using a
tunneling protocol to perform the state transition. The tunneling
protocol may be performed using, for example, a common gateway
protocol (CGP) or via an App Flow virtual channel itself.
[0234] In some embodiments, the first intermediary device may
negotiate with the first computing device and the second computing
device to re-establish the insights virtual channel from the second
intermediary device to the first intermediary device itself. The
negotiation may include determination of the highest or most recent
protocol version supported by all three devices in communicating
the analytics data via the insights virtual channel. Upon
negotiation, the first intermediary device may establish the
insights virtual channel between the first and the second computing
device through itself. With the re-establishment, the first
intermediary device may use the encryption method, key, and byte
information (e.g., the last byte) to decrypt the analytics data
previously exchanged across the insights virtual channel through
the second intermediary device. By decrypting, the first
intermediary device may identify or determine the last portion
(e.g., the last byte) of the analytics data exchanged through the
previous insights virtual channel. From the last portion, the first
intermediary device may commence exchanging of the analytics data
via the insights virtual channel between the first and second
computing devices.
[0235] The first intermediary device may access insights
communicated via the insights virtual channel (1330). Using the
received protocol state, the first intermediary device may
retrieve, identify, or otherwise access analytics data (sometimes
referred herein as insights) exchanged across the insights virtual
channel. In some embodiments, the first intermediary device may
initiate accessing of the analytics data in response to performance
of the state transition. The analytics data may be generated or may
originate from the first computing device or the second computing
device, and may include events and data points regarding the
communication session as described herein above. The first
intermediary device may identify the insights virtual channel from
a set of virtual channels established between the first and the
second computing device using the information. As discussed above,
the information may include, for example, the association between
the identifier of the protocol and the identifier of the virtual
channel or between the identifier of the protocol and the component
of the first computing device. With the identification of the
insights virtual channel, the first intermediary device may
identify, retrieve, or otherwise access the analytics data
exchanged between the first computing device and the second
computing device. In some embodiments, the first intermediary
device may use the encryption method, key, or byte information of
the protocol state to decrypt the analytics data exchanged through
the insights virtual channel. The analytics data may have been
encrypted prior to transmission by the first or the second
computing device. By decrypting, the first intermediary device may
recover the original analytics data.
Efficient Identification and Prioritization of Multi-Stream ICA
(MSI) HDX Streams
[0236] In multi-stream ICA (MSI), virtual channels may run on
different MSI streams with priority 0-3. The streams with different
priority can impart quality of service for the QoS for the virtual
channels. In Multi-port ICA, separate ports have to be configured
on the server-side agent 504 (e.g. VDA). A network device,
referenced here as SD-WAN by way of illustration, can support MSI
without multiple ports (e.g., using a single port) by deep parsing
CGP and ICA. In this manner, the SD-WAN can perform cross-session
caching and compression, thereby offloading reduction in
consumption of ICA bandwidth and printing image compression, among
other functionalities, via the data streams.
[0237] Referring now to FIG. 14, depicted is a block diagram of an
example representation of MSI using a client-side network device
604a and a server-side network device 604b. In system 1400,
although there can be any number of streams 1405 (e.g., MSI
streams), the embodiment shown and discussed herein provides for 4
MSI streams by way of illustration: 1 primary stream, which handles
the core ICA protocol and some VCs, and 3 secondary streams, which
handle additional VCs. In some embodiments, App Flow VC messages
are sent on the primary MSI stream, so a network device can parse
only the primary stream to access insights from these messages in
the App Flow VC. App Flow VC messages can also be sent on any other
pre-determined MSI stream, as long as the network device can know
or determine which stream to access the insights. To enable
identification of the separate streams, their type and priority,
stream-identifying data points can be initially sent on all MSI
streams, e.g. the one primary MSI stream and three secondary MSI
streams, as soon as each stream is created for instance. The
stream-identifying data points can include at least one of, but may
not be limited to: (a) Session GUID; (b) Stream ID; (c) Priority;
or (d) Stream type: Primary vs. Secondary. For example, a network
device (e.g., a Citrix SD-WAN) can use the priority to prioritize
HDX traffic accordingly.
[0238] During the lifetime of an HDX session, the priority of
individual VCs may change and they may be re-assigned to different
streams. This has no impact on the App Flow processing, since the
App Flow VC may always be processed on a predetermined (e.g.,
primary) stream. However, the priority of individual streams may
also change, in which case stream-identifying data points may be
sent again to indicate the change of priority. In some embodiments,
a VC write operation may normally send the data point only on the
dedicated stream associated with a VC, e.g. the primary stream in
case of the App Flow VC. But in the case of an App Flow
implementation, a modified VC write operation can be used to send
each stream-identifying data point on the respective stream, to
enable a network device to identify the separate streams, their
type and current priority.
[0239] Referring now to FIG. 15, depicted is a flow diagram of a
method 1500 of prioritizing data streams for virtual channels. The
method 1500 may be performed or implemented using any of the
components detailed herein, for example, the client 102, the server
106, the appliance 200, or the network device 604 (e.g., the
network devices 604a or 604b of the system 1400), among others. In
brief overview, a first intermediary device may establish data
streams comprising virtual channels (1505). The first intermediary
device may determine an identifier for each data stream (1510). The
first intermediary device may determine a priority for each data
stream (1515). The first intermediary device may send the
information on priority in data streams (1520). In some
embodiments, the functionalities of (1505)-(1520) may be performed
by the server 106 or the server-side agent 504 (e.g., VDA).
[0240] In further detail, a first intermediary device (e.g., the
network device 604a or 604b) may establish a set of data streams
(e.g., data streams 1405) each comprising one or more virtual
channels (e.g., virtual channels 508 or 506) (1505). Each data
stream may include one or more virtual channels established between
the first intermediary device and a second intermediary device
(e.g., the network device 604a or 604b). One of the data streams
may include an insights virtual channel to exchange analytics data
between the first intermediary device and the second intermediary
device. The establishment of the data streams including virtual
channels may be in accordance to any of the techniques described
herein in conjunction with FIGS. 5-14. The data stream may
communicate data used to present a graphical user interface of an
application hosted on one computing device (e.g., the server 106)
on a display of a recipient computing device (e.g., the client
102). The data may be communicated via the data stream in
accordance with a communications protocol, such as a multi-stream
ICA protocol or a remote desktop protocol, among others. Upon
establishment, the first intermediary device may transmit, receive,
or otherwise communicate data from the sets of data streams to one
of the computing devices (e.g., client 102 or the server 106). The
data from the data streams may be communicated from the first
intermediary device via a single port of the computing device.
[0241] The first intermediary device may determine an identifier
for each data stream (1510). The first intermediary device may
associate, assign, or otherwise determine the identifier of each
data stream among the set of data streams established between the
first computing device itself and the second computing device. The
identifier for a data stream may uniquely reference one data
stream, as distinguished from the other data streams in the set
established between the first intermediary device and the second
intermediary device. The identifier for the data stream may be, for
example, a globally unique identifier for a session (e.g., the
communication session supporting the set of data streams) or a
stream identifier, among others. The identifier may be a numeric
value or a set of alphanumeric strings, among others. In
determining the identifier, the first intermediary device may
create or generate the numeric value or the set of alphanumeric
strings. Upon generation, the first intermediary device may
associate or assign the identifier to the corresponding data
stream. In some embodiments, the first intermediary device may
determine the identifier in establishing the corresponding data
stream between the first and second intermediary devices.
[0242] The first intermediary device may determine a priority for
each data stream (1515). The first intermediary device may
associate, assign, or otherwise determine the priority of each data
stream among the set of data streams established between the first
intermediary device itself and the second intermediary device. The
priority of each data stream may define a level of precedence,
importance, urgency and/or quality of service of the data stream
among the set of data streams in communicating data between the
first intermediary device and the second intermediary device. For
example, data to be sent via data stream of a higher priority may
be sent prior to data to be sent via another data stream of a lower
priority. In some embodiments, to assign the priority, the first
intermediary device may identify a type of each data stream. In
some embodiments, in identifying the type of the data stream, the
first intermediary device may specify, identify or determine a type
of data communicated (or to be communicated) via the data stream.
The data transmitted via the data stream including the virtual
channels may include analytics data, audio, graphics, printer data,
disk data, and metadata, among others.
[0243] Based on the type of data (e.g., to be supported or
transmitted), the first intermediary device may classify, identify,
specify and/or determine the type of data stream. Each virtual
channel included in a data stream may be configured and/or
dedicated to delivering a particular type of data. The first
intermediary device may determine and/or specify the priority for
each data stream (including the data stream with the insights
virtual channel), corresponding to the type of the data stream. The
determination/specification of priority may be in accordance with a
listing of priorities for types of data streams and/or type(s) of
virtual channels that may be carried in each type of data stream.
For example, the listing may specify that the data stream carrying
analytics or voice data (e.g., via an analytics or voice VC) is to
have a higher priority than the data stream delivering printer
data. In some embodiments, the first intermediary device may
determine at least one of the data streams as a primary data stream
and at least one other of the data streams as a secondary data
stream. Data streams assigned as primary may be defined as taking
precedent or priority over data streams assigned as secondary.
[0244] The first intermediary device may send information in data
streams (1520). The first intermediary device may transmit,
provide, or otherwise send the information regarding the identifier
and priority for each data stream through the respective data
stream. For example, the first intermediary device may send the
identifier and priority for a data stream in the data stream itself
(e.g., in an insights VC or other VC of the data stream). The first
intermediary device may send the identifier and priority in a VC
that is uncompressed and/or non-interleaved with other VC(s) in the
data stream. The information may be accessed by another computing
device (e.g., an SD-WAN, a gateway, or another device in the
network link 518) between the first intermediary device and the
second intermediary device. In some embodiments, the first
intermediary device may commence sending the information over the
data stream, upon establishment between the first and second
intermediary devices. The information sent via the corresponding
data stream may include the identifier for the data stream, such as
the globally unique identifier for the session or the stream
identifier, among others. The information sent in the respective
data stream may include the priority for the data stream, such as:
the level of precedence/priority, the type of data stream, the type
of data to be exchanged/communicated via the data stream, and/or
the definition of the data stream as primary or secondary, among
others.
[0245] Subsequent to sending the information through the
corresponding data streams, the first intermediary device may
detect, identify, or otherwise determine an update to the
information for at least one of the data streams. The determination
may be repeated using the functionalities described above in (1510)
and (1515). The update to the information for the data stream may
lead to a change to the identifier or the priority, or both. For
example, the change to the identifier may include an updated
globally unique identifier for the session or an updated stream
identifier, among others. The change to the priority may include,
for example, an updated level of precedence/priority, the new type
of data stream, the new type of data to be exchanged via the data
stream, and/or the new definition of the data stream, among others.
Upon determining an update to the information, the first
intermediary device may send the new information regarding the
identifier and the priority for the data stream via the
corresponding data stream. The sending of the new information may
be performed in the same manner as the functionality in (1520). In
this manner, the sending of information via the data stream may be
performed through a single port, without reliance on multiple ports
by deep parsing CGP and ICA while providing compression and
cross-session caching of data transmitted.
L7 Latency Calculation and Communication Independent of Server
(Host) Processing Time
[0246] In some embodiments, ICA/HDX protocol determines Round Trip
Time (RTT) using measurement semantics that are different from a
level 7 (L7) latency measurement. The ICA/HDX RRT use semantics
that are geared towards user experience (UX) or application
response time. The ICA RTT calculation is based on a server's
response to a client's query. The server's response is sent on the
next outgoing packet. However, if an application does not perform
an update, e.g., a desktop application is idle, there is no other
server-to-client traffic. Hence, the next outgoing packet could be
indefinitely delayed, resulting in a measurement that may not be
useful.
[0247] An App Flow VC monitoring network device (such as NetScaler
Gateway or SD-WAN) may also be interested in reporting the
end-to-end network latency at Layer 7 of the OSI model between the
monitoring network device and the server (e.g., HDX host). This can
be an important or useful data point which reflects the network
conditions between the monitoring network device and the server,
and can also be combined with additional measurements of the
network conditions between the end-point and the monitoring
appliance for instance. In some embodiments, the network device can
calculate the L7 latency accurately by measuring the time taken for
a token, referred to as NsRTT (e.g., NetScaler Round Trip Token)
leaving the network device and returning back. The carrier channel
that brings back the NsRTT from the server includes Server
Processing Time (SPT), which can be deducted from the total time,
to obtain the actual "network device to server" L7 latency.
[0248] Calculating the SPT accurately can be very intricate by
virtue of the complex modules and systems involved. One novel
aspect lies in the way the system propagates information
(timestamp) between the discrete system components and then
assimilates it back. As illustrated in FIG. 16, in the sequence
1600, the network device 604 can receive a packet, such as an ICA
packet in an ICA stream (1605) from the receiver (e.g., the
client-side agent 502). The network device 604 can take a timestamp
T1 (1610) and insert a NsRTT token in the packet (e.g., in the ICA
packet in the ICA stream) to the server (1615). The server-side
WinStation Driver 1202 (sometimes referred to as WDICA) can receive
the NsRTT token, can take a timestamp T2 (1620), can record it
(e.g., in the Windows Event, using Event Tracing for Windows (ETW)
for instance), and can fire an event (1625) (e.g., one or more
functions specified by the initial packet to be performed), which
then goes into the Windows OS queue and later gets delivered to the
Citrix App Flow Service (CtxNsapSvc), for processing (1630). The
time it takes for the ETW to reach CtxNsapSvc can be
indeterministic.
[0249] The CtxNsapSvc, after receiving the ETW, can generate or
construct a payload (e.g., JSON payload), and can dispatch or
transmit it in an App Flow packet for instance (1635). The payload
can include the T2 timestamp previously communicated via the event.
Then, the WDICA, which is at a lower layer of the ICA stack and
essentially one layer above the network transport module, can
recalibrate, adjust, provide and/or update the SPT content in the
JSON payload by calculating the true SPT (T3-T2), where T3 is a
current timestamp taken by WDICA (e.g., the server-side WinStation
Driver 1602) upon receiving the payload or App Flow packet (1640).
The WDICA can write the true SPT in a field of the payload (e.g.,
JSON payload), and can transmit the packet to the network device
(1645). The network device 604, responsive to receiving the payload
in the packet, can take timestamp T4 and measure the true L7
latency using the SPT. The true L7 latency is equal to
T4-T1-(T3-T2) (1650). The network device 604 can send an NSAP
packet to the receiver (1655), and the receiver can discard the
packets (1660).
[0250] Referring now to FIG. 17, depicted is a flow diagram of a
method 1700 of calculating latency in application layer (L7)
communications independent of host server processing time. The
method 1700 may be performed or implemented using any of the
components detailed herein, for example, the client 102, the server
106, the appliance 200, or the network device 604, among others. In
brief overview, a device may receive a packet (1705). The device
may incorporate a token (e.g., flag, bit pattern, indicator,
cookie) into the packet at time T1 (1710). The device may cause a
duration D relative to time T2 (1715). The device may receive a
second packet at T3 (1720). The device may determine whether the
packet includes an identifier, e.g., of the device (1725). If the
identifier is included, the device may determine a round-trip
network time (1730). Otherwise, if the identifier is not included,
the device may bypass the determination of the round-trip network
time (1735).
[0251] In further detail, a device (e.g., the network device 604 or
another device in the network link 518) may receive a first packet
(1705). The device may identify, intercept, or receive the first
packet from another computing device (e.g., the client 102). The
first packet may be generated in accordance with an application
level protocol (L7), such as a remote desktop protocol (RDP), ICA
protocol, and HDX protocol, among others. The first packet may
include a header or a payload (sometimes referred herein as a body)
in accordance with the application level protocol. In some
embodiments, the payload may include a script in accordance with
any language, such as Extensible Markup Language (XML), JavaScript,
or JavaScript Object Notation (JSON), among others. Furthermore,
the first packet may be destined to a recipient (e.g., the server
106) as specified by one of the headers in the first packet. In
some embodiments, the first packet may correspond to a request by
the client to calculate the round-trip network time. Prior to
forwarding, the device may update or modify the first packet to
facilitate in calculation of round-trip network time.
[0252] The device may incorporate a token into the first packet at
time T1 (1710). Upon receipt of the first packet, the device may
generate the token (sometimes referred herein as a roundtrip token)
to include, insert, or otherwise incorporate into the first packet.
The token may be or include a numeric value or a set of
alphanumeric characters, and may indicate that the recipient device
is to facilitate in the calculation of the round-trip network time
between the device and recipient. In some embodiments, the device
may embed, add, or insert the token into a portion of the first
packet, such as the header and the payload. In some embodiments,
the device may also insert, include, or otherwise incorporate at
least one identifier (e.g., an entity identifier bit in an App Flow
capability) into the first packet upon receipt from the other
computing device. The identifier may be or include a numeric value
or a set of alphanumeric characters, and may be used to uniquely
reference the first packet in traveling through network (e.g., the
network link 518) to the recipient device and back to the device.
Upon generation, the device may embed, add, or insert the
identifier into a portion of the first packet, such as the header
or the payload. In incorporating the token (and the identifier),
the device may identify or otherwise record a time T1 at which the
first packet is transmitted to the server.
[0253] The device may cause a server to determine a duration D
relative to time T2 (1715). In sending the first packet to the
server, the device may trigger or cause the server or a driver
running on the server (e.g., the driver 1602) to receive the token.
With receipt of the first packet from the device, the server may
identify or record a time T2 at which the first packet is received
by the server. In some embodiments, upon receipt of the first
packet, the server may parse the first packet to extract, obtain,
or identify the token from the payload. With the identification of
the token, the server may commence determination of the duration D
relative to time T2. The duration D may measure or correspond to an
amount of time that the server consumes in handling or processing
the first packet (e.g., the remainder of the payload in the first
packet). In some embodiments, the server may maintain a timer to
count or keep track of the duration D.
[0254] In response to the first packet, the server may generate a
second token to send back to the device. By handling the first
packet, the server may cause an application (e.g., App Flow Service
or another program) hosted on the server to process the first
packet. Based on the received first packet, the application may
generate a payload to include the second token. Similar to the
first packet, the second packet may be generated in accordance with
an application level protocol (L7), such as a remote desktop
protocol (RDP), ICA protocol, and HDX protocol, among others. The
second packet may include a header or a payload in accordance with
the application level protocol. In some embodiments, the payload of
the second packet may include a script or information in accordance
with any language, such as Extensible Markup Language (XML),
JavaScript, or JavaScript Object Notation (JSON), among others.
Upon generation of the payload, the application may output, send,
or otherwise provide the payload to the driver on the server. The
driver in turn may insert, include, or otherwise incorporate the
payload into the second packet.
[0255] While the second token is generated, the server may use the
timer to keep track of the duration D in generating the second
token. Upon completion of the generation of the second packet, the
server may identify the time counted on the timer as the duration D
for generation of the second token. In some embodiments, the server
may also use the timer to keep track of time T2a at which the
driver is provided with the payload from the application running on
the server. Once identified, the server may determine the duration
D based on the times T2a and T2 (D=T2a-T2). With the determination,
the server may include, insert, or otherwise incorporate the
duration D into the second packet. In some embodiments, the server
may embed, add, or insert the duration D (or T2a and/or T2) into
the portion of the second packet, such as in the header or the
payload. In some embodiments, the server may insert, include, or
otherwise incorporate the same identifier from the first packet
into the second packet, such as in the header or the payload. Upon
incorporation, the server may provide, transmit, or send the second
packet with the duration D to the server.
[0256] The device may receive the second packet at T3 (1720).
Subsequent to the transmission, the device may receive the second
packet from the server. A set of virtual channels (e.g., virtual
channels 506 and 508) may have been established between the client
and the server through the device. At least one of the virtual
channels may be an insights virtual channel to exchange analytics
data between the client and the server. The insights virtual
channel may be separate from the other virtual channels and may be
non-interleaved with the other virtual channels. The communications
exchanged via the insights virtual channel may be uncompressed. The
device may receive the second packet via the insights virtual
channel from the server. In some embodiments, the header and the
payload of the second packet may also be uncompressed. Upon receipt
of the second packet, the device may record, determine or identify
time T3 at which the second packet was received by the device.
[0257] The device may determine whether the second packet includes
an identifier (1725). The identifier (e.g., in an entity ID bit or
field) may be incorporated into the first packet by the device and
into the second packet by the server to reference the packet
traveling to the server and back to the device. To determine this,
the device may parse the second packet (e.g., in the payload) to
extract, find, or identify the identifier. When the identifier is
found in the second packet, the device may determine that second
packet includes the identifier. On the other hand, when the
identifier is not found in the second packet, the device may
determine that the second packet does not include the
identifier.
[0258] If the identifier is included (e.g., indicating that the
second packet includes information intended for the device), the
device may determine a round-trip network time (sometimes referred
herein as the true L7 latency) (1730). The device may determine the
round-trip network time in accordance with time T3, T1, and D (or
T2a and T2). For example, the device may calculate the round-trip
network time as the difference of all three times, T3-T1-D. With
the determination, the device may record the round-trip network
time for the first packet. In some embodiments, the device may
include, insert, or incorporate the round-trip network time into
the second packet, such as in the header or the payload. Otherwise,
if the identifier is not included, the device may bypass the
determination of the round-trip network time (1735). The device may
forego the calculation of the round-trip network time. In any
event, the device may forward the second packet to the client
device. In some embodiments, the device may discard the second
packet received from the device. In some embodiments, the device
may identify the round-trip network trip (if inserted), prior to
discarding.
L7 Latency Calculation and Communication Between Multiple Network
Devices
[0259] The App Flow VC capability described in connection with
FIGS. 15 and 16 may be extended to include an additional field,
where each entity (network device or client) may set a previously
unused bit as the App Flow VC capability travels from the server to
the client (e.g., in an ICA init-request packet). The bit (or
field) can be used to uniquely identify each entity. Each entity
can record the bit it uses as an Entity ID bit, and can set it in
the App Flow VC capability so that it does not get used by other
downstream entities.
[0260] When a network device inserts an NsRTT token in the ICA
stream, the network device can also update or decorate the token
with its corresponding Entity ID bit. As the NsRTT token travels in
the client-to-server direction, the NsRTT token may also be reused
by other network devices in the path by each adding/setting its
corresponding Entity ID bit.
[0261] The SPT computation and the creation of L7 latency App Flow
data point at the server can proceed as described above, except
that the server can insert the combined Entity ID bits in the L7
latency App Flow data point. Each network device in the path can
interpret the L7 latency App Flow data point as described above,
except that the network device can ignore the data point unless it
has its specific assigned Entity ID bit set.
[0262] Various elements, which are described herein in the context
of one or more embodiments, may be provided separately or in any
suitable sub-combination. For example, the processes described
herein may be implemented in hardware, software, or a combination
thereof. Further, the processes described herein are not limited to
the specific embodiments described. For example, the processes
described herein are not limited to the specific processing order
described herein and, rather, process blocks may be re-ordered,
combined, removed, or performed in parallel or in serial, as
necessary, to achieve the results set forth herein.
[0263] It should be understood that the systems described above may
provide multiple ones of any or each of those components and these
components may be provided on either a standalone machine or, in
some embodiments, on multiple machines in a distributed system. The
systems and methods described above may be implemented as a method,
apparatus or article of manufacture using programming and/or
engineering techniques to produce software, firmware, hardware, or
any combination thereof. In addition, the systems and methods
described above may be provided as one or more computer-readable
programs embodied on or in one or more articles of manufacture. The
term "article of manufacture" as used herein is intended to
encompass code or logic accessible from and embedded in one or more
computer-readable devices, firmware, programmable logic, memory
devices (e.g., EEPROMs, ROMs, PROMs, RAMs, SRAMs, etc.), hardware
(e.g., integrated circuit chip, Field Programmable Gate Array
(FPGA), Application Specific Integrated Circuit (ASIC), etc.),
electronic devices, a computer readable non-volatile storage unit
(e.g., CD-ROM, USB Flash memory, hard disk drive, etc.). The
article of manufacture may be accessible from a file server
providing access to the computer-readable programs via a network
transmission line, wireless transmission media, signals propagating
through space, radio waves, infrared signals, etc. The article of
manufacture may be a flash memory card or a magnetic tape. The
article of manufacture includes hardware logic as well as software
or programmable code embedded in a computer readable medium that is
executed by a processor. In general, the computer-readable programs
may be implemented in any programming language, such as LISP, PERL,
C, C++, C#, PROLOG, or in any byte code language such as JAVA. The
software programs may be stored on or in one or more articles of
manufacture as object code.
[0264] While various embodiments of the methods and systems have
been described, these embodiments are illustrative and in no way
limit the scope of the described methods or systems. Those having
skill in the relevant art can effect changes to form and details of
the described methods and systems without departing from the
broadest scope of the described methods and systems. Thus, the
scope of the methods and systems described herein should not be
limited by any of the illustrative embodiments and should be
defined in accordance with the accompanying claims and their
equivalents.
[0265] It will be further understood that various changes in the
details, materials, and arrangements of the parts that have been
described and illustrated herein may be made by those skilled in
the art without departing from the scope of the following
claims.
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