U.S. patent application number 16/682265 was filed with the patent office on 2020-03-12 for customized domain names in a content delivery network.
This patent application is currently assigned to Level 3 Communications, LLC. The applicant listed for this patent is Level 3 Communications, LLC. Invention is credited to Mark Brady, David Fullagar, Gifford Neal Hesketh, Christopher Newton.
Application Number | 20200084083 16/682265 |
Document ID | / |
Family ID | 46507421 |
Filed Date | 2020-03-12 |
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United States Patent
Application |
20200084083 |
Kind Code |
A1 |
Hesketh; Gifford Neal ; et
al. |
March 12, 2020 |
CUSTOMIZED DOMAIN NAMES IN A CONTENT DELIVERY NETWORK
Abstract
A computer-implemented method, operable in a content delivery
network (CDN) including a plurality of cache servers and domain
name servers. At a cache server in the CDN, a first domain name is
obtained, the first domain name being associated with a client
request for a resource from the cache server. One or more values
associated with the client request are determined and a second
domain name is generated, including information from the first
domain name and information relating to the one or more values
associated with the client request. The second domain name is
provided to the client. A domain name server in the CDN obtains a
request to resolve a first domain name; extracts one or more keys
and one or more corresponding values from the first domain name,
and generates a second domain name based on the first domain name,
the second domain name excluding information from the first domain
name relating to the one or more keys and the one or more values.
The name server resolves the second domain name using at least some
of the one or more values extracted from the first domain name.
Inventors: |
Hesketh; Gifford Neal;
(Newbury Park, CA) ; Newton; Christopher;
(Westlake Village, CA) ; Brady; Mark; (San Rafael,
CA) ; Fullagar; David; (Boulder, CO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Level 3 Communications, LLC |
Broomfield |
CO |
US |
|
|
Assignee: |
Level 3 Communications, LLC
Broomfield
CO
|
Family ID: |
46507421 |
Appl. No.: |
16/682265 |
Filed: |
November 13, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13348348 |
Jan 11, 2012 |
10484232 |
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16682265 |
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61432197 |
Jan 12, 2011 |
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61432195 |
Jan 12, 2011 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04L 67/1014 20130101;
H04L 67/327 20130101; H04L 61/35 20130101; H04L 61/301 20130101;
H04L 61/303 20130101; H04L 29/1265 20130101; H04L 29/12783
20130101; H04L 61/1511 20130101; H04L 29/12066 20130101; H04L
67/2842 20130101; H04L 61/305 20130101 |
International
Class: |
H04L 29/12 20060101
H04L029/12; H04L 29/08 20060101 H04L029/08 |
Claims
1-10. (canceled)
11. A computer-implemented method, operable in a content delivery
network (CDN) comprising a plurality of cache server sites and a
domain name system including one or more domain name servers
configured to provide domain name resolution, and, the method
comprising: (A) at a domain name server in the CDN, obtaining a
request to resolve a first domain name; (B) extracting one or more
keys and one or more corresponding values from said first domain
name; (C) generating a second domain name based on said first
domain name, said second domain name excluding information from
said first domain name relating to said one or more keys and said
one or more values; and (D) resolving said second domain name using
at least some of the one or more values extracted from the first
domain name.
12. The method of claim 11 wherein the one or more values
associated with the client request include one or more of: an
network address of a client; a type of device associated with the
client; a type of content associated with a client request; an
identification of the requested resource; and a data transmission
rate.
13. The method of claim 12 wherein the network address is an
Internet Protocol (IP) address of the client.
14. The method of claim 12 wherein the type of device is selected
from: phone, computer, television, set-top box.
15. The method of claim 12 wherein the domain name server in the
CDN performs policy-based name resolution using at least some of
the one or more values extracted from the first domain name.
16-22. (canceled)
Description
RELATED APPLICATIONS
[0001] This application is related to and claims priority from the
following co-owned and co-pending U.S. Provisional patent
applications, the entire contents of each of which are fully
incorporated herein by reference for all purposes: [0002]
Application No. 61/432,195, filed Jan. 12, 2011, titled
"Redirection Of Network Traffic," (attorney docket no. 0382-US-P1)
[0003] Application No. 61/432,197, filed Jan. 12, 2011, titled
"Redirection Of Network Traffic," (attorney docket no.
0382-US-P2)
BACKGROUND OF THE INVENTION
Copyright Statement
[0004] This patent document contains material subject to copyright
protection. The copyright owner has no objection to the
reproduction of this patent document or any related materials in
the files of the United States Patent and Trademark Office, but
otherwise reserves all copyrights whatsoever.
FIELD OF THE INVENTION
[0005] This invention relates to content delivery and content
delivery networks. More specifically, to content delivery networks
and systems, frameworks, devices and methods supporting content
delivery and content delivery networks.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Other objects, features, and characteristics of the present
invention as well as the methods of operation and functions of the
related elements of structure, and the combination of parts and
economies of manufacture, will become more apparent upon
consideration of the following description and the appended claims
with reference to the accompanying drawings, all of which form a
part of this specification.
[0007] FIG. 1 depicts operation of a domain name system;
[0008] FIG. 2 depicts a content delivery network (CDN);
[0009] FIG. 3 depicts operation of the CDN of FIG. 2;
[0010] FIGS. 4-5 depict exemplary logical organization/structure of
the CDN of FIG. 2;
[0011] FIG. 6 depicts operation of a CDN using customized domain
names;
[0012] FIGS. 7a-7d are flowcharts depicting aspects of operation of
embodiments of CDNs using customized domain names;
[0013] FIG. 7e depicts operation of an embodiment of a CDN using
customized domain names;
[0014] FIG. 8 depicts communication via a directory system; and
[0015] FIG. 9 is a schematic diagram of a computer system.
DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EXEMPLARY
EMBODIMENTS
Glossary
[0016] As used herein, unless used otherwise, the following terms
or abbreviations have the following meanings:
[0017] CDN means content delivery network;
[0018] DNS means Domain Name System;
[0019] FQDN means Fully Qualified Domain Name;
[0020] HTTP means Hyper Text Transfer Protocol;
[0021] IP means Internet Protocol;
[0022] IP address means an address used in the Internet Protocol to
identify electronic devices such as servers and the like;
[0023] URI means Uniform Resource Identifier; and
[0024] URL means Uniform Resource Locator.
BACKGROUND AND OVERVIEW
[0025] The Domain Name System (DNS)
[0026] An IP address is a numerical label assigned to each device
(e.g., computer) participating in a computer network such as the
Internet that uses the Internet Protocol for communication. An IP
address functions for host or network interface identification and
for location addressing. Although IP addresses are numbers, they
are usually stored and displayed using notations, such as, e.g.,
162.16.24.11 (for Internet Protocol Version 4--IPv4), and
2001:db8:0:2345:0:567:1:2 (for Internet Protocol Version
6--IPv6).
[0027] In networks such as the Internet, computers (e.g., servers)
are typically organized (logically) in an hierarchical system of
domains. Each computer has at least one network address (e.g., an
IP address) that is used, inter alia, by other computers to connect
to that computer. Each computer may also be associated with one or
more domains, and, in that regard, each computer has one or more
hostnames that can be used to map (directly or otherwise) to the
computer's network address. Examples of domains (and domain names)
are ".com", ".net", ".gov", "cnn.com", "wipo.int", "uspto.gov",
"www.weather.com", "a.b.cdn.net", and so on. A hostname is a domain
name (preferably a fully qualified domain name--FQDN) that
identifies a particular computer (or group of computers) in a
network.
[0028] The process of obtaining one or more network addresses
associated with a hostname is called domain name resolution (or
sometimes just name resolution). Name resolution is generally
performed by a domain name system (DNS)--more specifically, by one
or more name servers in a DNS.
[0029] A domain name system is an hierarchical system that is used,
inter alia, to resolve domain names--i.e., to map domain names to
corresponding network addresses or to other domain names. As shown,
e.g., in FIG. 1, Domain Name System 102 is made up of one or more
name servers 104-1, 104-2, . . . , 104-k (collectively referred to
as name servers 104).
[0030] Network domains may be organized hierarchically, to include
one or more sub-domains. Thus, e.g., the domain name "a.b.cdn.net"
corresponds to a sub-domain "a" ("a.b.cdn.net") in a sub-domain
"b.cdn.net" in a sub-domain "cdn.net" in a sub-domain "net"
(actually in a sub-domain ".") There may be one or more DNS name
servers that are responsible for name resolution in each domain and
sub-domain. At least one name server must be authoritative for name
resolution in each domain and sub-domain.
[0031] In the domain name "a.b.cdn.net", the domain "net" (or
".net") is considered a top-level domain, with "cdn.net" being the
next domain below it, and so on.
[0032] The process of name resolution for a domain name generally
involves providing the domain name to a DNS name server which
either provides an answer or queries a name server that should know
the answer.
Resources and Uniform Resource Locators (URLS)
[0033] As used herein, resources may be any static or dynamic data
item comprising an arbitrary sequence of bits, regardless of how
those bits are stored or transmitted, and regardless of what those
bits represent. A resource provided by a CDN may comprise data
representing some or all of another resource, including some or all
of: a file, a portion of a file, a digital message, a portion of a
digital message, a digital image, a portion of a digital image, a
video signal, a portion of a video signal, an audio signal, a
portion of an audio signal, a software product, a portion of a
software product, a page in memory, a web page, a movie, and a
portion of a movie. This list is given by way of example, and is
not intended to be in any way limiting.
[0034] In networks such as the Internet, resources are identified
by URLs (or URIs), and client requests for resources are generally
made using URLs (or URIs) for those resources, each resource
typically being identified by its own URL (or URI). URLs are
defined in Network Working Group RFC 1738, "Uniform Resource
Locators (URL)", by T. Berners-Lee et al., URIs are described in
Network Working Group RFC 2396, "Uniform Resource Identifiers
(URI): Generic Syntax," by T. Berners-Lee et al., August, 1998, the
entire contents of both of which are fully incorporated herein for
all purposes.
[0035] A URL has the form: [0036]
<<protocol>>://<<domain>>/<<path>>
where <<protocol>> may be, e.g., "http", "https",
"ftp", "rtmp", and so on; <<domain>> is a domain name
(generally a fully qualified domain name--FQDN); and where
<<path>> specifies a location of the resource in the
domain.
[0037] When a client computer requests a resource using a URL
(e.g., using a browser or the like), the hostname associated with
that URL must be mapped to a computer (or computers) having that
resource. With reference again to FIG. 1, by way of example, the
client 106 (or a resolver on the client 106) passes the hostname
(e.g., "<<domain>>" in the example above) associated
with the URL to the DNS 102 (at S1) and receives back from the DNS
one or more network addresses (IP addresses) of one or more servers
108 identified by the hostname in the URL (at S2). The client may
then connect to server 108 using a network address obtained from
the DNS, using a port number taken from the URL (or implicitly
specified by protocol), and request the resource identified by the
<<path>> portion of the URL (at S3), the style of the
request being determined by the protocol of the URL. The server 108
then serves the requested resource to the client (at S4).
[0038] Typically a client has a DNS name server associated
therewith, and the client's resolver will make name resolution
requests to that name server. That name server may be a name server
of the client's service provider (ISP). The client's name server
interacts with other name servers 104 in the DNS 102 in order to
resolve a hostname or domain name.
[0039] Content Delivery Networks (CDNS)
[0040] Networks that are engaged to deliver electronic resources,
such as video, images, audio files, documents, software and the
like, to end users on the Internet on behalf of owners or providers
of those resources ("content providers") are commonly referred to
as Content Delivery Networks (CDNs). A primary purpose of a CDN is
to distribute resources efficiently to client machines on behalf of
one or more content providers, preferably via a public Internet.
Both end-users (clients) and content providers benefit from using a
CDN. By using a CDN, a content provider is able to take pressure
off of its own servers. Clients benefit by being able to obtain
content with fewer delays.
[0041] An example of a CDN is shown in FIG. 2, and represented as
CDN 110. An exemplary CDN 110 will typically have multiple points
of presence, or cache cluster sites 112-1, 112-2, . . . 112-m
(collectively caches 112), located across a wide geographic area. A
CDN 110 also includes other components (collectively denoted 114 in
FIG. 2) such as, e.g., components for control, administration,
rendezvous, operation, measurement, etc. The CDN's rendezvous
system 116 and selector system 118 are described in greater detail
below.
[0042] Exemplary operation or use of the CDN 110 is described with
reference to FIGS. 2 and 3. When a particular client (e.g., client
120) wants to obtain a particular resource, that client is
typically directed to a "best" (or "optimal") location (via
rendezvous system 116 in conjunction with the selector system 118).
As used here, a location may be, e.g., a server, a server site, a
region of servers, a cache cluster, a cache cluster site, etc. The
location may be another CDN or network or a server outside the CDN
110. The "best" or "optimal" location may be, without limitation, a
cache cluster site, a cache cluster, a group, a tier, or some
combination thereof.
[0043] Those of skill in the art will realize and understand, upon
reading this description, that the notion of a "best" location is
dependent on multiple factors, including, without limitation, some
or all of the following: network load, load on the CDN servers and
other components, location of the client computer, etc. The notion
of a "best" location may vary by time of day, type of content,
content provider policies, CDN policies, etc. The invention is not
to be limited in any way by the manner in which a "best" location
in the CDN is determined.
[0044] The rendezvous system 116 is thus used to direct client
resources requests, usually to cache sites 112 in the CDN 110. The
rendezvous system 116 uses, e.g., a selector mechanism 118 in order
to direct clients requests to a location (e.g., cache cluster site
112-1) that is "optimal" or "best" for that client at that
time.
[0045] The rendezvous system 116 is preferably implemented using
the domain name system and comprises one or more DNS name servers.
The rendezvous mechanism preferably includes domain name servers
implementing policy-based domain name resolution. Exemplary
rendezvous systems 116 are described in U.S. Pat. Nos. 7,822,871
and 7,860,964, the entire contents of each of which are fully
incorporated herein for all purposes.
[0046] The selector mechanism 118 may be fully or partially
integrated into the rendezvous system 116. The "best" server may be
selected by a server selection mechanism such as described in U.S.
Pat. No. 6,185,598, the entire contents of each of which are fully
incorporated herein for all purposes. In a presently preferred
implementation, the server selection mechanism is part of and uses
the DNS system.
[0047] With reference to FIGS. 2-3, an exemplary use of the CDN 110
(in which the client 120 wants to obtain a particular resource) is
as follows:
[0048] The client computer 120 interacts with the rendezvous system
116 in order to determine the "best" location from which to obtain
the particular resource (at S1). When the rendezvous system 116 is
integrated into the DNS system (as shown by the dotted line in FIG.
3) the client's DNS system 122 interacts with the CDN's rendezvous
system 116 to direct the client to a location, preferably in the
CDN 110, from which the client can obtain the resource. When the
rendezvous system 116 is integrated into the DNS system, this
request (at S1) may be part of a request to resolve a domain name
associated with the particular resource, and the rendezvous
mechanism may provide the client with one or more IP addresses or
CNAMEs of one or more locations in the CDN (at S2).
[0049] Those of skill in the art will realize and understand, upon
reading this description, that the name server(s) of the CDN 110
are invoked as part of the name resolution process for hostnames
(or domain names) for which the CDN is authoritative.
[0050] Having obtained a "best" location from which to obtain the
particular resource, the client computer 120 then requests the
particular resource from the location(s) in the CDN 110 (at S3a)
specified by the one or more IP addresses. The CDN 110 may already
have a copy of that particular resource at that location, in which
case it provides (serves) the resource to the client computer 120
(at S3b). If the CDN did not already have a copy of that particular
resource at that location, then it tries to obtain a copy at that
location (either from another location in the CDN or from the
content provider 124) (at S4a, S4b). Having obtained the resource
(either from another location in the CDN or from the content
provider 124), the CDN 110 provides (serves) the resource to the
client computer 120 (at S3b).
[0051] CDN Logical Structure
[0052] A CDN may have one or more tiers of caches, organized
hierarchically. FIG. 4 depicts a content delivery network 400 that
includes multiple tiers of caches. Specifically, the CDN 400 of
FIG. 4 shows j tiers of caches (denoted Tier 1, Tier 2, Tier 3, . .
. , Tier j in the drawing). Each tier of caches may comprise a
number of caches organized into cache groups. A cache group may
correspond to a cache cluster site or a cache cluster. The Tier 1
caches are also referred to as edge caches, and Tier 1 is sometimes
also referred to as the "edge" or the "edge of the CDN." The Tier 2
caches (when present in a CDN) are also referred to as parent
caches.
[0053] For example, in the CDN 400 of FIG. 4, Tier 1 has n groups
of caches (denoted "Edge Cache Group 1", "Edge Cache Group 2", . .
. , "Edge Cache Group n"); tier 2 (the parent caches' tier) has in
cache groups (the i-th group being denoted "Parent Caches Group
i"); and tier 3 has k cache groups, and so on. Preferably each tier
has the same number of cache groups, although this is not
required.
[0054] FIG. 5 shows the logical organization/grouping of caches in
a CDN of FIG. 4. In the exemplary CDN 400 of FIG. 5, each tier of
caches has the same number (n) of cache groups. Those of skill in
the art will know and understand, upon reading this description,
that each cache group may have the same or a different number of
caches. Additionally, the number of caches in a cache group may
vary dynamically. For example, additional caches may be added to a
cache group to deal with increased load on the group.
[0055] The caches in a cache group may be homogenous or
heterogeneous, and each cache in a cache group may comprise a
cluster of physical caches sharing the same name and/or network
address. An example of such a cache is described in co-pending and
co-owned U.S. published Patent Application No. 2010-0332664, and in
U.S. Pat. No. 8,015,298, titled "Load-Balancing Cluster," issued
Sep. 6, 2011, the entire contents of each of which are fully
incorporated herein by reference for all purposes.
[0056] Caches in the same tier and the same group are sometimes
referred to as peers or peer caches. In general, for each Tier j,
the caches in Tier j are peers of each other, and the caches in
Tier j+1 are parent caches.
[0057] A typical CDN has only one or two tiers of caches. A CDN
with only one tier will have only edge caches, whereas a CDN with
two tiers will have edge caches and parent caches. (At a minimum, a
CDN should have at least one tier of caches--the edge caches.)
[0058] The grouping of caches in a tier may be based, e.g., on
their physical or geographical location. For example, a particular
CDN may have six groups--four groups of caches in the United
States, group 1 for the West Coast, group 2 for the mid-west, Group
3 for the northeast and Group 4 for the south east; and one group
each for Europe and Asia.
[0059] Those of skill in the art will realize and understand, upon
reading this description, that cache groups may correspond to cache
clusters or cache cluster sites.
[0060] A particular CDN cache is preferably in only one cache
group.
[0061] In general, some or all of the caches in each tier can
exchange data with some or all of the caches in each other tier.
Thus, some or all of the parent caches can exchange information
with some or all of the edge caches, and so on. For the sake of
simplicity, in the drawing (FIG. 4), each tier of caches is shown
as being operationally connectable to each tier above and below it,
and Tier 3 is shown as operationally connected (via 402 in FIG. 4)
to Tier 1 (the Edge Tier). In some CDNs, however, it may be
preferable that the caches in a particular tier can only exchange
information with other caches in the same group (i.e., with peer
caches) and/or with other caches in the same group in a different
tier. For example, in some CDNs, the edge caches in edge cache
group k, can exchange information with each other and with all
caches in parent cache group k, and so on.
[0062] A content provider's/customer's server (or servers) are also
referred to as origin servers. A content provider's origin servers
may be owned and/or operated by that content provider or they may
be servers provided and/or operated by a third party such as a
hosting provider. The hosting provider for a particular content
provider may also provide CDN services to that content provider.
With respect to a particular subscriber/customer resource, a
subscriber/customer origin server is the authoritative source of
the particular resource. More generally, with respect to any
particular resource (including those from elements/machines within
the CDN), the authoritative source of that particular resource is
sometimes referred to as an origin server.
[0063] A CDN may also include a CDN origin/content cache tier which
may be used to cache content from the CDN's subscribers (i.e., from
the CDN subscribers' respective origin servers). Those of skill in
the art will know and understand, upon reading this description,
that a CDN can support one or more content providers or
subscribers, i.e., that a CDN can function as a shared
infrastructure supporting numerous content providers or
subscribers. The CDN origin tier may also consist of a number of
caches, and these caches may also be organized (physically and
logically) into a number of regions and/or groups. The cache(s) in
the CDN origin tier obtain content from the content
providers'/subscribers' origin servers, either on an as needed
basis (a pull) or in advance (via a push).
[0064] Customized Domain Names
[0065] As described above, the CDN preferably uses the domain name
system (and DNS name servers) to perform various operations,
including rendezvous, policy control, etc. When a client makes a
request for a resource using a URL, regardless of what information
is available in the URL itself, and regardless of what information
is available when an HTTP request is made, for the first part of
the process--the name resolution part--the DNS name servers see
only a domain name (a hostname or FQDN). For example, for the
exemplary URL: [0066] http://domain_name/path the DNS name servers
are only provided with the hostname "domain_name", and not with the
path or protocol information.
[0067] It should be noted that if a URL contains a domain name that
is not a FQDN, the resolver may complete (or expand) the domain
name to make it a FQDN prior to giving it to the DNS.
[0068] The inventors realized that it would be beneficial to
provide additional information to the rendezvous system and to
other systems in the DNS in order, e.g., to be able to provide
improved rendezvous and/or policy control.
[0069] Accordingly, as described below, in various embodiments, the
DNS system is provided with customized domain names, preferably
customized at request time. These customized domain names may
include any information available to HTTP and from HTTP headers. As
will also be described below, in various embodiments the customized
domain names can be used by a name server to collect information
and to make static and/or dynamic assessments of aspects of the
network.
[0070] According to example embodiments, a customized domain name
can comprise, but is not limited to, information/attributes
associated with the requesting client computer (e.g., IP address of
the client computer), the requested content's title or identifier,
an encoding associated with the requested content, a device
associated with the end-user (e.g., PC, set-top box, etc.), a
protocol associated with delivery of the requested content, a
downloadable identifier associated with the requested content
and/or CDN, a bitrate associated with delivery of the requested
content, a popularity metric/value associated with the requested
content, a service level associated with the requesting end-user
and/or content provider, a signature and/or token authentication
associated with the customized domain name, etc. In general,
customized domain names can include any information that could be
included in an HTTP header (including the URI) and any information
that could be known/available at the time of the HTTP request.
[0071] A customized domain name may be generated by one or more of:
a name server (e.g., the client's name server), a content provider,
a cache server or cache server site, an origin server or origin
server site, a browser script, a resolver, a browser, in addition
to any other entity suitable for generating domain names. For
example, a browser script may modify URLs (or hostnames for URLs)
in a web page. This modification may be made when the web pages are
initially loaded or when requests are made for resources embedded
in those pages.
[0072] There are two types of information that may be included in a
customized domain name. The first type of information is
information for which the DNS system will need specific values. An
example of this first type of information includes the client's IP
address. The second type of information is information that may be
classified in some way, e.g., the type of content requested, what
kind of device the client is (e.g., phone, television, computer,
etc.), and so on.
[0073] In one embodiment, each item of information encoded in a
customized domain name has an associated key or tag, e.g., "i" for
IP address, "b" for bit rate, "m" for machine type, etc. If a
particular item of information is to be included in the customized
domain name, then the key for that item must also be included as
part of that name. Preferably the keys for all values are
concatenated to form a string, e.g., "imb" to mean that the domain
name will include values for the IP address, the machine type and
the bit rate, in that order. In general, if there are n keys with
keys k.sub.1, k.sub.2, . . . , k.sub.n to be included in a domain
name, in that order, the keys are concatenated for form the string
"k.sub.1k.sub.2 . . . k.sub.n". The values corresponding to those
keys (which may be specific values or classifications) are to
follow the keys in the same order as the keys.
[0074] So, for example, suppose that a particular request includes
a URL: [0075] http://PQR.CDN.net/path/ABC.mov (URL 1) and that this
request is being made from a television set with an IP address of
123.234.12.125. Suppose, for this example, that the "i" is the key
for IP address, "b" for bit rate, and "m" for machine type, and
that the code for a television is "t". An exemplary corresponding
customized domain name may be: [0076]
PQR.im.123.234.12.125.t.CDN.net (D1)
[0077] In this example (D1 above), the bit rate is not encoded. The
IP address is encoded as 123.234.12.125, and the machine type is
encoded as "t" for television.
[0078] When the customized domain name D1 is sent to the domain
name system, it will be sent to a name server for the domain
"CDN.net". That name server will parse the domain name to extract
the key/value pairs, and then resolve the name "PQR.CDN.net",
possibly using some or all of the information that was provided
with the key/value pairs.
[0079] Those of skill in the art will realize and understand, upon
reading this description, that the format and key names described
are given by way of example, and that other formats and key names
may be provided. It should be appreciated, however, that any
encoding should resolve at least to the domain of a name server
that can, at least, extract the original domain name from the
modified domain name. In the case of a CDN, with domain names
written as described above, the right side of the modified domain
preferably includes the domain of the CDN.
[0080] Those of skill in the art will realize and understand, upon
reading this description, that some or all of the values in the
key/value pairs may be encoded or encrypted.
[0081] As noted above, some of the values of some of the keys
comprise information (e.g. encoding rate, client device type) that
may be classified in some way. This information may, in some
embodiments be hashed in order to encode the classification
information. Even if the original information may not be obtainable
from a hash of the value for some types of information, hashing of
values may still be useful to differentiate between two values
(e.g., to determine whether or not two values are equal or
different). For example, an encoding rate or some other information
may be hashed in order to provide a value for comparison against a
future or prior hash of the same data. In these cases the hash
value essentially provides a one-way encoding function. However,
since two identical values will be encoded the same way by the same
hash function, the initial (un-encoded) versions of any two values
can be compared for equality. Values that can be hashed are values
where the specific value is not meaningful, but which being able to
differentiate such opaque values is of interest.
[0082] For instance, the following domain name represents an
example customized domain name associated with particular requested
content, content provider B, and content delivery network C: [0083]
B.xyz.x.sub.h x.sub.h x.sub.h x.sub.h y.sub.h y.sub.h y.sub.h
y.sub.h x.sub.h z.sub.h z.sub.h z.sub.h (D2) In this example
customized domain name D2, "B" (or a similar identifier) indicates
content provider B, "xyz" are keys of key-value pairs that indicate
the information/attributes included in the customized domain name
(e.g., x=client IP address, y=title of requested content, and
z=bitrate associated with delivery of the requested content),
"x.sub.h x.sub.h x.sub.h x.sub.h" indicates the tokenized hash
value of "x" for that particular key-value pair, "y.sub.h y.sub.h
y.sub.h y.sub.h" indicates the tokenized hash value of `y` (e.g.,
title of requested content) for that particular key-value pair,
"z.sub.h z.sub.h z.sub.h z.sub.h" indicates the tokenized hash
value of `z` (e.g., bitrate associated with delivery of the
requested content) for that particular key-value pair, and "C.com"
(or similar identifier) indicates the domain for content delivery
network C. Note that, at least in this example domain name, since
there are three keys "xyz", a name server will understand (e.g.,
during parsing of the hostname) that three respective value pairs
will follow in the domain name. Further note that any combination
of keys (i.e., zero or more keys) can be used in the domain name in
any given order. For example, the ordering can indicate the
relative weight or importance a given key/attribute should receive
with respect to redirection of the request within CDN. It should be
further noted that the configuration and representation of the
content provider identifier, the zero or more key-value pairs, the
content delivery network identifier, and/or any other information
suitable for use in domain names, are not limited to the example
embodiment/domain name provided above, and are contemplated to be
configured and/or represented in any order or fashion associated
with generating, parsing, administering, etc., domain names.
[0084] It should be appreciated that the domain name D2 above is a
customized version of the following domain name D3: [0085] B.C.com
(D3)
[0086] Recall that the name server(s) of the CDN 110 are invoked as
part of the name resolution process for hostnames (or domain names)
for which the CDN is authoritative. Therefore, in this case, since
"C" is the content delivery network (i.e., "C.com" is a domain of
the CDN), the processing of all information to the left of "C.com"
in domain name D2 (or D3) is performed by the DNS names server(s)
of the CDN.
[0087] Note that there is no requirement that C.com identify the
CDN--for example, C.com may be in a subdomain of the customer
domain that is delegated to the CDN.
[0088] There are a number of locations in the system at which
domain names may be usefully rewritten. These include: (1) at the
client (e.g., in the resolver); and (2) at a cache server in the
CDN or the origin server.
[0089] A client's resolver (e.g., resolver 605 in FIG. 6) or some
other mechanism on the client may be modified to rewrite domain
names (as described herein) for certain kinds of requests (e.g.,
request to certain domains or to indicate the original FQDN being
requested (i.e., to embed the name into the CNAME returned from an
initial inquiry) or to include the requestors (the client) IP
address).
[0090] A cache server (e.g., edge cache server 612 and/or parent
cache server 614) or an origin server 616 may be modified to
rewrite domain names (as described herein) for certain kinds of
requests. In these cases, the clients may be redirected to
different cache servers. Once a client has been directed to a cache
server and has an HTTP connection with that cache server, the cache
server knows some information about the client and about the
request that the DNS system did not know. For example, the cache
server knows the client's IP address and it knows information that
was included in the HTTP headers that were used to make the
connection. That cache server can then modify the domain name in
the URL that was used to make the request and redirect the client
(e.g., with an HTTP REDIRECT instruction) to the URL with the
modified domain name.
[0091] The client will then make the request again, this time using
the modified URL with the modified domain name. Since the DNS will
have extra information encoded in the modified domain name, it may
be able to make a better cache site selection for that client
request. As described below, in some cases the request is not
directed to a different server.
[0092] Those of skill in the art will realize and understand, upon
reading this description, that for requests for small objects
(e.g., small image files that are part of a web page), it may not
be worthwhile to redirect a client request (since the redirection
time may exceed the time it would take to actually serve the
content). However, for large objects (such as movies and for
streamed objects), the overhead of modifying the domain name and
redirecting the client may be worth the benefits.
[0093] In some embodiments a hostname may be modified to include an
indication of the actual resource being requested. E.g., for URL1
from above (http://PQR.CDN.net/path/ABC.mov), the modified hostname
could include/encode "path/ABC.mov" in some manner. For example,
the modified hostname may look like "path_ABC_mov.PQR.CDNnet"
(perhaps including other information too). In this way the DNS will
actually know exactly which resource is being requested when it
selects a server in the CDN. It should be appreciated that the
actual name of the resource (in this example "path/ABC.mov" or
"ABC.mov") may be encoded.
Example
[0094] FIG. 6 illustrates an example network environment suitable
for implementing various embodiments disclosed herein. The example
network environment of FIG. 6 comprises a content delivery network
602 and an end-user/client 604 (e.g., end user device such as a PC,
laptop, mobile device, etc., and/or media player or similar content
playback application executed by such a device). The example
network configuration further comprises a content delivery network
602.
[0095] The client 604 is operable to issue a request for content
associated with a content provider (e.g., a request for movie ABC
associated with content provider PQR). The request may have been an
HTTP request associated with a URL of the form: [0096]
http://PQR.CDN.net/path/ABC.mov (URL2) which includes a domain name
(hostname "PQR.CDN.net"). The domain name associated with the
request may be associated with the CDN 602, and may be
modified/customized to be of the form: [0097]
PQR.XyZ.x.sub.valuey.sub.valuez.sub.value.CDN.net (D4)
[0098] The customized domain name can comprise information and/or
attributes associated with, for example, but not limited to, an
end-user, the particular content being requested, the location of
the client, and the like.
[0099] Still referring to FIG. 6, the content delivery network 602
comprises a DNS 608 made up of one or more CDN name servers 610.
These CDN name servers 610 are part of the CDN's rendezvous system
606 and are configured to receive and process, for example,
requests to resolve domain names, wherein the domain names can
comprise customized domain names as described above. As shown in
the drawing, the DNS 608 includes a parser 611 that extracts
encoded information from customized domain names.
[0100] In this example configuration, CDN 602 comprises one or more
edge caches/servers 612, one or more mid-tier and/or parent
caches/servers 614, and origin cache/server(s) 616 associated with
the content provider specified in the customized domain name. The
origin cache/server(s) 616 may be situated within the CDN 602. In
another example embodiment, the network configuration comprises (in
addition to or in lieu of origin cache/server(s) 616) origin
cache/server(s) 616-B situated outside of CDN 602 (e.g., situated
within the content provider domain and/or network).
[0101] The customization/modification of the domain name may take
place, e.g., at the client 604 using modifier routine(s) 613
(possibly integrated into the client's resolver 605), and/or at the
cache servers using modifier routines 613 associated therewith.
While each group of cache servers (612, 614, 616) is shown in the
drawing as having modifier routines 613 associated therewith, it
should be appreciated that in a particular implementation, some or
all of the individual cache servers will each have modifier
routines associated therewith. It should also be appreciated that
in some implementations the clients or the caches may not have
modifier routines associated therewith.
[0102] In order to resolve a customized name (e.g., D3), the client
604 (the client's resolver 605) invokes or calls a DNS name server
(i.e., a name server in the DNS system 618) that is associated with
end-user/client 604. The client's name server passes the name
resolution request (directly or indirectly) to the CDN DNS 608 and
thus to a CDN name server 610 associated with the CDN domain (in
this example, "CDN.net").
[0103] Depending on the CDN name server 610's processing/parsing of
the customized domain name, the CDN name server 610 (and/or a
selector 118 associated therewith) selects as a location (or
domain) one of: an edge cache server 612, a parent cache server
614, origin cache/server 616, or origin cache/server 616-B (or to
another CDN).
[0104] The rendezvous system (via name server 610 and DNS 618) then
provides an address (e.g., an IP address) or CNAME corresponding to
the selected location or domain to the client 604 via the client's
name server.
[0105] The client then makes the request from a server associated
with one of the address or domain.
[0106] Those of skill in the art will realize and understand, upon
reading this description, that customized domain names can provide
more efficient and streamlined administration, data management,
dynamic processing/redirection/delivery, etc., of content with
respect to popularity.
[0107] For example, if a customizable domain name comprises
information and/or attributes related to the particular content
that is being requested, the CDN's rendezvous system 606, using CDN
name server 610, can determine a respective popularity value or
metric associated with the requested content and redirect the
request within CDN 602 accordingly. For example, if the
information/attributes associated with a requested movie indicate
that the requested movie is relatively popular (e.g., via
processing performed by name server 610), then CDN name server 610
can select an edge cache server 612 to serve or deliver the
requested movie. If, on the other hand, the requested movie is
deemed to be relatively unpopular, then CDN name server 610 can
select a cache server configured in one or more intermediate tiers
between edge servers and origin servers), or even origin servers to
serve the requested movie.
[0108] It should be appreciated that the rendezvous system 606 (and
its components name server(s) 610 do not themselves serve the
requested content to the client. They provide the client with a
location (e.g., address or domain) from which the client may
request the content. That address or domain may be a location
(e.g., cache/server/cluster) within the CDN or it may be outside
the CDN (e.g., an content provider server or another CDN).
[0109] Customized domain names can provide other advantages (in and
of themselves, or in addition to the advantages discussed above
with respect to content popularity) by providing improved
redirection (e.g., rendezvous) of requests to caches/servers within
CDN 602. The selector system (selector 118 in FIG. 2) preferably
uses location information about the requesting client in order to
select an "optimal" or "best" location from which the client should
request a resource. However, a selector system often does not know
an exact location (network location or otherwise) of the requesting
client, and must often make assumptions about that location.
[0110] For example, in a conventional configuration, a name server
would not have knowledge of where a requesting client is physically
or logically located or of the network address of the client. Thus,
e.g., the CDN name server 610 (and thus the selector 118) may only
know the location of a name server associated with the client
(e.g., via an IP address of that name server). The client's name
server may be located in a vastly different location than the
requesting end-user. As such, since the selector system 118
associated with CDN name server 610 uses location information, it
would rendezvous requests from the client to locations that it
considers "optimal" or "best" for the client's name server (even
though those locations are potentially sub-optimal for the actual
client).
[0111] Thus, in some embodiments, a customized domain name
comprises an address associated with an end-user/client (e.g., IP
address of client 604). Using this information, name server 610
(and the selector system 118 associated therewith) can determine a
more appropriate rendezvous location for requests from that
client.
[0112] It is useful for a CDN's rendezvous system to make
resolution decisions based on information related to the content
being requested. For example, the rendezvous system may direct
clients to different levels in the CDN based on some measure (e.g.,
static or dynamic) of popularity of the requested resource. If
information about a requested resource can be included in a
modified domain name, then the rendezvous system (e.g., the DNS
name servers) can use that information to direct resource requests.
The rendezvous system can also use that information to keep track
of requested resources.
[0113] FIG. 7a is a flowchart of various actions performed by a
customized domain name routine, and FIG. 7b is a flowchart of
various actions performed by a CDN name server (or a name server
authoritative for the domain).
[0114] With reference to FIG. 7a, the routine obtains the original
domain name (at 702), e.g., from the URL or as part of an HTTP
request. The routine determines the values for various items and
thereby determines one or more key/value pairs (at 704). The
routine then constructs the modified domain name (at 706) using the
various key/value pairs. Some of values may be encoded and/or
encrypted.
[0115] With reference to FIG. 7b, the CDN name server receives a
domain name (at 708) as part of a request for name resolution (and,
e.g., rendezvous). The CDN name server extracts any key/value pairs
from the domain name (at 710) and constructs or determines the
original domain name (at 712). For example, for the modified domain
name D2 above, the original domain name is: [0116] B.C.com (D5) The
original domain name can be constructed or determined, e.g., by
removing the key-value pairs and associated information.
[0117] The CDN name server then resolves the original domain name,
preferably using at least some of the extracted information (at
714). For example, if the key-value pairs included appropriate
information, the CDN DNS may use one or more of the attribute
values to determine a popularity value associated with the
requested content. Similarly, if the key-value pairs include an
attribute value associated with the requesting client's IP address,
the CDN DNS (or the selector associated therewith) may use that
information to determine a location associated with the client.
[0118] FIG. 7c is a flowchart of various actions performed in an
exemplary CDN using customized domain names as described above.
[0119] The client makes an HTTP request using a first URL (having a
first domain name--hostname) (at 716).
[0120] The first domain name (hostname) is extracted from first URL
and is used to direct client to a first cache cluster site (at
718).
[0121] The client then makes an HTTP connection with a first cache
server at the first cache cluster site (at 720).
[0122] The first cache server at first cache cluster site modifies
first domain name (at 722) (e.g., as described with reference to
FIG. 7a), encoding some information about request and/or about
client (e.g., client's IP address, type of request, bit rates,
identification of content, account information, etc.).
[0123] The first cache server creates a modified URL from first
URL, the modified URL having the modified version of the first
domain name, and redirects client to the modified URL (at 724).
[0124] The client receives the redirect instruction (which includes
the modified URL with the customized domain name) and makes an HTTP
request using the modified URL with the customized domain name (at
726).
[0125] The CDN's DNS receives the customized domain name (as part
of the name resolution process) and processes it, e.g., as
described with reference to FIG. 7b, sending the client IP
address(es) of cache cluster site(s) determined using the modified
domain name (at 728).
[0126] The client receives the information from the domain name
server (e.g., IP addresses of cache cluster site(s) determined
using the modified domain name) and the client makes an HTTP
connection using that information (at 730).
[0127] Those of skill in the art will realize and understand, upon
reading this description, that a client should not be repeatedly
redirected by the cache clusters, and so a flag or other
information may be provided, e.g., in an HTTP header, to prevent
repeated redirection. This may also be achieved by, e.g., detection
of the fact that key-value data has been introduced in the
hostname, or by an indicator in the path. Those of skill in the art
will realize and understand, upon reading this description, that
the client may be sent back to the first cache server (by the CDN's
DNS in 728) intentionally (as described below) or if, by
happenstance, that server turns out to be the "best" or "optimal"
server for that client.
[0128] Those of skill in the art will realize and understand, upon
reading this description, that there is a certain amount of
overhead associated with request redirection, and excessive
redirection may adversely affect overall system performance as well
as a particular clients experience. Accordingly, while the
flowchart in FIG. 7c shows client requests being redirected with
modified URLs, it should be appreciated that any particular
embodiment or implementation may selectively redirect only certain
client requests. For example, a cache cluster site may chose to
redirect a client request depending on whether or not that site
already has the requested resource. As another example, a cache
cluster site may redirect only a small percentage of requests
(e.g., 1 in 10,000 requests). Those of skill in the art will
realize and understand, upon reading this description, that these
selective redirection criteria may be combined with each other and
that different and/or other redirection criteria may be used.
[0129] FIG. 7d is a flowchart of various actions performed in an
exemplary CDN using customized domain names. In the example in FIG.
7d, only some of the client requests are redirected using modified
URLs, and, in addition, preferably the client request is redirected
back to the cache cluster site from which the client request was
redirected.
[0130] With reference to FIG. 7e and the flowchart in FIG. 7d, the
client makes a request with a first URL (at 732). The domain name
is extracted from the first URL and is used to determine a cache
cluster site in the CDN 602 from which the requested content will
be served (at 734). In this processing, the extracted domain name
(also referred to as the first domain name) is sent to the DNS
system 618 (step 1 in FIG. 7e) by the client's resolver. The DNS
system, using CDN name server(s) 610 that are authoritative for the
first domain resolve the first domain to one or more locations
(e.g., cache cluster sites or cache servers) in the CDN 602. The
CDN name server(s) 610 may use the selector mechanism 118 to select
a location in the CDN to handle this request. The DNS system
provides the client 604 with one or more IP addresses corresponding
to the location(s) selected by the CDN (e.g., by the CDN rendezvous
mechanism 606) (step 2 in FIG. 7e).
[0131] The client uses one of the one or more IP addresses to make
a connection with a cache server 612 (or cache server site) in the
CDN (at 736, step 3 in FIG. 7e). (For this discussion, the cache
server to which the client connects is referred to as the first
cache server.)
[0132] The first cache server receives the client request and
determines (at 738) whether or not this particular request should
be redirected using a modified URL. If the request is not to be
redirected, the client is served by the first cache server (at 740)
in the manner described above (the first cache server may have to
obtain the required content from another location such as a peer
server or an origin server before serving it to the client).
[0133] The determination (at 738) as to whether to redirect the
client request (with a modified URL) may be made based on a number
of factors, including some or all of the following criteria: [0134]
1. No more than one in every x requests are redirected, where x may
be, e.g., 10,000. [0135] 2. Only redirect requests for which the
first cache server already has the content. Since, in this
embodiment, the client will be redirected back to the first cache
server, applying this particular criterion will mean that if a
client is redirected then that client will not also have to wait,
upon its return, for the first cache server to obtain the requested
content. [0136] 3. Do not redirect any request that was already
redirected. [0137] 4. Redirect some percentage of requests of a
certain type or for certain content providers.
[0138] Those of skill in the art will realize and understand, upon
reading this description, that different and/or other criteria may
be used to redirect client requests.
[0139] If the first cache server determines (at 738) that the
client request is to be redirected (at 742 and step 4 in FIG. 7e),
then the first cache server creates a modified domain name based,
at least in part, on the domain name that was used by the client in
the initial request. The modified domain name preferably contains
information about the client and/or about the request. This
information preferably includes information from the HTTP headers
and information that was used by the client to make the HTTP
request to the first cache server. It will be appreciated that the
first cache server has access (e.g., from the HTTP headers) that
was not available to the DNS system when the first domain name was
resolved. By encoding this information into a modified or
customized domain name, the DNS system will be able to obtain
information about the client and/or about the network. Such
information may be used by the DNS system in subsequent name
resolution. Since the client will be redirected back to the first
cache server, the modified domain name preferably includes an IP
address of the first cache server.
[0140] The first cache server creates a modified URL (using the
modified domain name) and redirects the client to the modified URL
(at 744, and Step 5 in FIG. 7e). The first cache server may use an
HTTP "REDIRECT" instruction or some other appropriate redirection
technique to perform the redirection.
[0141] Upon receipt of the redirect instruction with the modified
URL, the client 604 extracts the customized/modified domain name
and provides it to the DNS system 618 for resolution (at 746, step
6 in FIG. 7e). The modified domain name is processed by the name
server(s) 610 to extract information encoded therein (at 748) and
then the name server provides the client with the IP address of the
first cache server (step 7 in FIG. 7e). Since the modified domain
name includes an IP address of the first cache server, the name
server 610 can determine where to send the client request.
[0142] The client makes a connection with the first cache server
(at 750, 8 in FIG. 7e), and requests the content.
[0143] The first cache server serves the content to the client (740
and step 9 in FIG. 7e).
[0144] As an example, suppose that the first request is made with
URL1 [0145] http://PQR.CDN.net/path/ABC.mov (URL 1) from client X
with an IP address 123.234.212.123. The original hostname
"PQR.CDN.net" is used by the DNS and the selector to direct the
client to a particular first cache server (e.g., at IP address
222.111.123.10). That first cache server modifies the first URL to
include a modified hostname which includes the first cache server's
IP address. It should be appreciated that each cache server may
have multiple IP addresses, and the cache server may chose which IP
address to use in the rewriting. In this way the cache server may
use some of the IP addresses to avoid subsequent redirection. In
this example a modified hostname may look something like:
IP_from_222_111_123_10_IP_Client_123_234_212_123_Content_Movie.PQR.CDN.net-
.
[0146] In this example the modified hostname (above) includes an
encoding of the client's IP address, an encoding of an IP address
of the first cache server, and information (possibly encoded) about
the content being requested ("Content_Movie").
[0147] In some cases the client's IP address may be included in the
modified hostname. In this way, the DNS system can get some or all
of the following information about the network: [0148] client IP
(from modified hostname) [0149] resolver IP (source IP of the DNS
queries and where the DNS responses are sent); [0150] cache IP
(from modified hostname; also first DNS choice, given resolver IP
as input).
[0151] Those of skill in the art will realize and understand, upon
reading this description, that the hostname is modified in a manner
that allows the name server's parser to extract the encoded and
embedded information.
[0152] Using this approach, the DNS system can determine useful
information about the network. E.g., a DNS name server can
determine where resolvers are relative to their clients. Often the
location of a resolver can be used as an approximation of the
location of a client, and it is preferable to know where a resolver
(and a client) actually are located in a network.
[0153] Some content providers (e.g., streaming video providers) may
know more about their customers than other providers. These content
providers may require registration or the like, and they may use
that information to obtain information about their customers. In
addition, certain content providers (e.g., again, steaming video
providers) may require their end users to use specific client-side
systems. For instance, a streaming video provider may require its
users to use certain client-side software for accounting purposes
as well as for rendering content. In these cases, the content
provider's client-side software can modify URLs before the initial
request. In these cases, when a cache server gets the first request
from a client, that request has already been made using a modified
URL (modified by the client-side program). As with the previous
examples, the information provided in the modified domain names can
be collected by the DNS name servers for use in the current and/or
subsequent processing.
[0154] Those of skill in the art will realize and understand, upon
reading this description, that the name server(s) may act as
collectors of information, and that they may provide this
information to one or more other mechanisms for processing.
[0155] While the description above has focused on the HTTP
protocol, it should be appreciated that other protocols may be used
(e.g., RTSP for streaming media, and SIP used for VoIP). Those of
skill in the art will realize and understand, upon reading this
description, that the invention is not limited by the particular
protocol described herein, and any system that uses a DNS to
resolve a hostname is contemplated herein.
[0156] In addition, although the description above has focused, by
way of example, on content delivery and CDNs, other aspects and
uses are contemplated, and those of skill in the art will realize
and understand, upon reading this description, that other
applications of the system may be used.
[0157] Although described herein using a DNS, it should be
appreciated that, in some aspects, a DNS provides a directory
service (providing a mapping from keys to corresponding values).
Thus, at one level, the system provides a generic IPC
(Inter-process communication) mechanism for networked agents,
incorporating the use of a directory service (e.g., DNS). In the
case of a CDN, the agents are generally two or more of the HTTP
server, the HTTP client, and the DNS server. However, as will be
appreciated by those of skill in the art, upon reading this
description, other application protocols and other agents are
contemplated.
[0158] For example, as shown in FIG. 8, an agent (Agent A) 802 may
provide information to a directory system 804 by means of a request
R1. The request R1 may encode information for use by the directory
system 804 (or by some other agent (e.g., Agent B, 806). The
directory system 804 may provide a response to Agent A (e.g., R2),
although, as shown by the dotted line in FIG. 8, the response may
be optional.
[0159] The request R1 may encode information in the form of a
specially created key for use by the directory system 804. For
example, as shown in the description above, the directory system
804 may comprise a DNS system, and the key may comprise a FQDN.
[0160] Information encoded in the request R1 may be extracted by
the directory system 804 and used to determine or provide a
response R2 to Agent A (the requestor). Some or all of that
information may be provided (alone or with other information from
other requests) to a second agent (Agent B, 806) in the drawing. It
should be appreciated that Agent A has no direct communication with
(and possibly no knowledge of) Agent B, and that information from
Agent A is communicated to Agent B via the directory system
804.
[0161] Information in a request (e.g., R1) may be used
transactionally, as part of filling that request (e.g., to generate
the response R2). Information in a request may also (or instead) be
collected and/or reported elsewhere for later use. The later use
may be by the directory system itself or by some other entity or
agent. Information may be used and reported alone or in some
consolidated form.
[0162] In the general case, information provided in the request R1
from Agent A to the directory system may be encoded in the form of
key-value pairs (as duplex data), as monadic tokens (simplex data),
as lists of monadic values (tuple data); or as one-to-many
key-value sets (multiplex data).
[0163] In the above description, the so-called "agents" may be
processes, in which case the so-called "directory system" provides
a mechanism for one process (agent A) to communicate with another
process (agent B).
[0164] In the context of the CDN described above, the directory
system 804 corresponds to a DNS (e.g., DNS 122 in FIG. 3), and
Agent A corresponds, e.g., to client 120 in FIG. 3.
[0165] Computing
[0166] Programs that implement such methods (as well as other types
of data) may be stored and transmitted using a variety of media
(e.g., computer readable media) in a number of manners. Hard-wired
circuitry or custom hardware may be used in place of, or in
combination with, some or all of the software instructions that can
implement the processes of various embodiments. Thus, various
combinations of hardware and software may be used instead of
software only.
[0167] FIG. 9 is a schematic diagram of a computer system 800 upon
which embodiments of the present disclosure may be implemented and
carried out.
[0168] According to the present example, the computer system 800
includes a bus 801 (i.e., interconnect), at least one processor
902, at least one communications port 903, a main memory 904, a
removable storage media 905, a read-only memory 906, and a mass
storage 907.
[0169] Processor(s) 902 can be any known processor, such as, but
not limited to, an Intel.RTM. Itanium.RTM. or Itanium 2.RTM.
processor(s), AMD.RTM. Opteron.RTM. or Athlon MP.RTM. processor(s),
or Motorola.RTM. lines of processors, and the like. Communications
port(s) 903 can be any of an RS-232 port for use with a modem based
dial-up connection, a 10/100 Ethernet port, a Gigabit port using
copper or fiber, or a USB port, and the like. Communications
port(s) 903 may be chosen depending on a network such as a Local
Area Network (LAN), a Wide Area Network (WAN), a CDN, or any
network to which the computer system 900 connects. The computer
system 900 may be in communication with peripheral devices (e.g.,
display screen 930, input device(s) 916) via Input/Output (I/O)
port 909.
[0170] Main memory 904 can be Random Access Memory (RAM), or any
other dynamic storage device(s) commonly known in the art.
Read-only memory 906 can be any static storage device(s) such as
Programmable Read-Only Memory (PROM) chips for storing static
information such as instructions for processor 902. Mass storage
907 can be used to store information and instructions. For example,
hard disks such as the Adaptec.RTM. family of Small Computer Serial
Interface (SCSI) drives, an optical disc, an array of disks such as
Redundant Array of Independent Disks (RAID), such as the
Adaptec.RTM. family of RAID drives, or any other mass storage
devices may be used.
[0171] Bus 901 communicatively couples processor(s) 902 with the
other memory, storage and communications blocks. Bus 901 can be a
PCI/PCI-X, SCSI, a Universal Serial Bus (USB) based system bus (or
other) depending on the storage devices used, and the like.
Removable storage media 905 can be any kind of external
hard-drives, floppy drives, IOMEGA.RTM. Zip Drives, Compact
Disc--Read Only Memory (CD-ROM), Compact Disc--Re-Writable (CD-RW),
Digital Video Disk--Read Only Memory (DVD-ROM), etc.
[0172] Embodiments herein may be provided as a computer program
product, which may include a machine-readable medium having stored
thereon instructions, which may be used to program a computer (or
other electronic devices) to perform a process. As used herein, the
term "machine-readable medium" refers to any medium, a plurality of
the same, or a combination of different media, which participate in
providing data (e.g., instructions, data structures) which may be
read by a computer, a processor or a like device. Such a medium may
take many forms, including but not limited to, non-volatile media,
volatile media, and transmission media. Non-volatile media include,
for example, optical or magnetic disks and other persistent memory.
Volatile media include dynamic random access memory, which
typically constitutes the main memory of the computer. Transmission
media include coaxial cables, copper wire and fiber optics,
including the wires that comprise a system bus coupled to the
processor. Transmission media may include or convey acoustic waves,
light waves and electromagnetic emissions, such as those generated
during radio frequency (RF) and infrared (IR) data
communications.
[0173] The machine-readable medium may include, but is not limited
to, floppy diskettes, optical discs, CD-ROMs, magneto-optical
disks, ROMs, RAMs, erasable programmable read-only memories
(EPROMs), electrically erasable programmable read-only memories
(EEPROMs), magnetic or optical cards, flash memory, or other type
of media/machine-readable medium suitable for storing electronic
instructions. Moreover, embodiments herein may also be downloaded
as a computer program product, wherein the program may be
transferred from a remote computer to a requesting computer by way
of data signals embodied in a carrier wave or other propagation
medium via a communication link (e.g., modem or network
connection).
[0174] Various forms of computer readable media may be involved in
carrying data (e.g. sequences of instructions) to a processor. For
example, data may be (i) delivered from RAM to a processor; (ii)
carried over a wireless transmission medium; (iii) formatted and/or
transmitted according to numerous formats, standards or protocols;
and/or (iv) encrypted in any of a variety of ways well known in the
art.
[0175] A computer-readable medium can store (in any appropriate
format) those program elements which are appropriate to perform the
methods.
[0176] As shown, main memory 904 is encoded with application 950-1
that supports the functionality as discussed herein (the
application 950-1 may be, e.g., the parser 611 or the modifier
613). Application 950-1 (and/or other resources as described
herein) can be embodied as software code such as data and/or logic
instructions (e.g., code stored in the memory or on another
computer readable medium such as a disk) that supports processing
functionality according to different embodiments described
herein.
[0177] During operation of one embodiment, processor(s) 902
accesses main memory 904 via the use of bus 901 in order to launch,
run, execute, interpret or otherwise perform the logic instructions
of the application 950-1. Execution of application 950-1 produces
processing functionality in content delivery process 950-2. In
other words, the content delivery process 950-2 represents one or
more portions of the application 950-1 performing within or upon
the processor(s) 902 in the computer system 900.
[0178] It should be noted that, in addition to the content delivery
process 950-2 that carries out operations as discussed herein,
other embodiments herein include the application 950-1 itself
(i.e., the un-executed or non-performing logic instructions and/or
data). The application 950-1 may be stored on a computer readable
medium (e.g., a repository) such as a floppy disk, hard disk or in
an optical medium. According to other embodiments, the application
950-1 can also be stored in a memory type system such as in
firmware, read only memory (ROM), or, as in this example, as
executable code within the main memory 904 (e.g., within Random
Access Memory or RAM). For example, application 950-1 may also be
stored in removable storage media 905, read-only memory 906, and/or
mass storage device 907.
[0179] Example functionality supported by computer system 900 and,
more particularly, functionality associated with application 950-1
is discussed above with reference to FIGS. 6 and 7a-7b.
[0180] Those skilled in the art will understand that the computer
system 900 can include other processes and/or software and hardware
components, such as an operating system that controls allocation
and use of hardware resources.
[0181] As discussed herein, embodiments of the present invention
include various steps or operations. A variety of these steps may
be performed by hardware components or may be embodied in
machine-executable instructions, which may be used to cause a
general-purpose or special-purpose processor programmed with the
instructions to perform the operations. Alternatively, the steps
may be performed by a combination of hardware, software, and/or
firmware. The term "module" refers to a self-contained functional
component, which can include hardware, software, firmware or any
combination thereof.
[0182] One of ordinary skill in the art will readily appreciate and
understand, upon reading this description, that embodiments of an
apparatus may include a computer/computing device operable to
perform some (but not necessarily all) of the described
process.
[0183] Embodiments of a computer-readable medium storing a program
or data structure include a computer-readable medium storing a
program that, when executed, can cause a processor to perform some
(but not necessarily all) of the described process.
[0184] Where a process is described herein, those of skill in the
art will appreciate that the process may operate without any user
intervention. In another embodiment, the process includes some
human intervention (e.g., a step is performed by or with the
assistance of a human).
[0185] It should be appreciated that the words "first" and "second"
in the claims are used to distinguish or identify, and not to show
a serial or numerical limitation. Similarly, the use of letter or
numerical labels (such as "(a)", "(b)", and the like) are used to
help distinguish and/or identify, and not to show any serial or
numerical limitation or ordering.
[0186] While the invention has been described in connection with
what is presently considered to be the most practical and preferred
embodiments, it is to be understood that the invention is not to be
limited to the disclosed embodiment, but on the contrary, is
intended to cover various modifications and equivalent arrangements
included within the spirit and scope of the appended claims.
* * * * *
References