# Patent

## Title
Latency measurement in resource requests

## Abstract

Systems and method for the management and processing of resource requests by a service provider, such as a content delivery network (“CDN”) service provider, on behalf of a content provider are provided. The CDN service provider can measure the performance associated with the delivery of resources to a requesting client computing devices from various computing devices associated with the CDN service provider. In one embodiment, a client computing device can execute code, such as scripts, that cause the client computing device to transmit requests to different computing devices associated with the CDN service provider's domain. Information associated with the processing of the responses can be used to measure CDN service provider latencies.

## Background
BACKGROUND
Generally described, computing devices and communication networks can be utilized to exchange information. In a common application, a computing device can request content from another computing device via a communication network. For example, a user at a personal computing device can utilize a software browser application to request a Web page from a server computing device via the Internet. In such embodiments, the user computing device can be referred to as a client computing device and the server computing device can be referred to as a content provider.
Content providers are generally motivated to provide requested content to client computing devices, often with consideration of efficient transmission of the requested content to the client computing device and/or consideration of a cost associated with the transmission of the content. For larger scale implementations, a content provider may receive content requests from a high volume of client computing devices, which can place a strain on the content provider's computing resources. Additionally, the content requested by the client computing devices may have a number of components, which can further place additional strain on the content provider's computing resources.
With reference to an illustrative example, a requested Web page, or original content, may be associated with a number of additional resources, such as images or videos, which are to be displayed with the Web page. In one specific embodiment, the additional resources of the Web page are identified by a number of embedded resource identifiers, such as uniform resource locators (“URLs”). In turn, software on the client computing devices typically processes embedded resource identifiers to generate requests for the content. Often, the embedded resource identifiers reference computing devices associated with the content provider such that the client computing devices would transmit requests for resources to the referenced content provider computing devices.
Some content providers attempt to facilitate the delivery of requested content, such as Web pages and/or resources identified in Web pages, through the utilization of a content delivery network (“CDN”) service provider. A CDN service provider typically maintains a number of computing devices in a communication network that can maintain content from various content providers. In turn, content providers can instruct, or otherwise suggest to, client computing devices to request some, or all, of the content provider's content from the CDN service provider's computing devices.
CDN service providers are also generally motivated to provide requested content to client computing devices, often with consideration of efficient transmission of the requested content to the client computing device or consideration of a cost associated with the transmission of the content. Typically, CDN service providers often consider factors such as latency of delivery of requested content in order to meet service level agreements or generally improve the quality of delivery service. In turn, the CDN service provider can utilize the considered factors in processing resource requests.



BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a block diagram illustrative of content delivery environment including a number of client computing devices, a content provider, and a content delivery network service provider;
FIG. 2 is a block diagram of the content delivery environment of FIG. 1 illustrating the registration of a content provider with a CDN service provider;
FIG. 3 is a block diagram of the content delivery environment of FIG. 1 illustrating the generation of resource requests by a client computing device;
FIGS. 4A-4C are block diagrams of the content delivery environment of FIG. 1 illustrating the generation of multiple embedded resource requests by a client computing device based on the execution of executable code;
FIG. 5 is a flow diagram illustrative of a resource identifier processing routine implemented by a client computing device;
FIG. 6 is a block diagram of the content delivery environment of FIG. 1 illustrating the registration of a content provider with a CDN service provider;
FIG. 7 is a block diagram of the content delivery environment of FIG. 1 illustrating the generation of resource requests by a client computing device;
FIG. 8 is a block diagram of the content delivery environment of FIG. 1 illustrating the generation of resource requests by a client computing device responsive to a redirection command provided by a CDN service provider;
FIG. 9 is a flow diagram illustrative of a resource request processing routine implemented by a CDN service provider;
FIG. 10 is a block diagram of the content delivery environment of FIG. 1 illustrating the generation of resource requests by a client computing device;
FIG. 11 is a block diagram of the content delivery environment of FIG. 1 illustrating the protocol interaction between a client computing device and multiple Points of Presence associated with a CDN service provider; and
FIG. 12 is a flow diagram illustrative of a resource request processing routine implemented by a CDN service provider.



DETAILED DESCRIPTION
Generally described, the present disclosure is directed to managing resource requests for one or more resources associated with a content provider. Specifically, aspects of the disclosure will be described with regard to the management and processing resource requests by a service provider, such as a content delivery network (“CDN”) service provider, on behalf of a content provider. Illustratively, the CDN service provider can measure the performance associated with the delivery of resources to a requesting client computing devices from various computing devices associated with the CDN service provider. In one embodiment, client computing devices can be provided executable code, such as scripts, that cause the client computing device to transmit requests to different computing devices associated with the CDN service provider's domain. Information associated with the processing of the responses can be used to measure CDN service provider latencies. In another embodiment, the CDN service provider can utilize commands responsive to an initial request for a resource that causes the requesting client computing device to transmit one or more supplemental resource requests to computing devices associated with the CDN service provider's domain. Information associated with the processing of the sequence of resource requests can be used to measure CDN service provider latencies. In a further embodiment, the CDN service provider can utilize commands corresponding to communication protocols that cause the requesting client computing device to transmit or receive protocol information from multiple computing devices associated with the CDN service provider's domain. Information associated with the processing of the protocol responses can be used to measure CDN service provider latencies
Although various aspects of the disclosure will be described with regard to illustrative examples and embodiments, one skilled in the art will appreciate that the disclosed embodiments and examples should not be construed as limiting. For example, the present disclosure may be described with regard to request routing services provided by a service provider, such as a CDN service provider, that may provide additional services and functionality including network-based storage services, caching services, application hosting, or other services. However, one skilled in the relevant art will appreciate that a service provider need not provide all, or any, of the additional services or functionality that may be associated with some service providers, such as a CDN service provider. Additionally, although various embodiments will be described with regard to the measurement of performance or latencies associated with the processing of resource requests, one skilled in the relevant art will further appreciate that the various embodiments may be practiced independently or combined in various manners.
FIG. 1 is a block diagram illustrative of content delivery environment 100 for the management and processing of content requests. As illustrated in FIG. 1, the content delivery environment 100 includes a number of client computing devices 102 (generally referred to as clients) for requesting content from a content provider and/or a CDN service provider. In an illustrative embodiment, the client computing devices 102 can corresponds to a wide variety of computing devices including personal computing devices, laptop computing devices, hand-held computing devices, terminal computing devices, mobile devices, wireless devices, various electronic devices and appliances and the like. In an illustrative embodiment, the client computing devices 102 include necessary hardware and software components for establishing communications over a communication network 108, such as a wide area network or local area network. For example, the client computing devices 102 may be equipped with networking equipment and browser software applications that facilitate communications via the Internet or an intranet.
Although not illustrated in FIG. 1, each client computing device 102 can utilize some type of local DNS resolver component, such as a DNS Name server, that generates the DNS queries attributed to the client computing device 102. In one embodiment, the local DNS resolver component may be provide by an enterprise network to which the client computing device 102 belongs. In another embodiment, the local DNS resolver component may be provided by an Internet Service Provider (ISP) that provides the communication network connection to the client computing device 102. However, for purposes of the present disclosure, communications facilitated through a network component, such as a DNS Resolver component, will be illustrated as transmitted directly from the client computing devices 102.
The content delivery environment 100 can also include a content provider 104 in communication with the one or more client computing devices 102 via the communication network 108. The content provider 104 illustrated in FIG. 1 corresponds to a logical association of one or more computing devices associated with a content provider. Specifically, the content provider 104 can include a web server component 110 corresponding to one or more server computing devices for obtaining and processing requests for content (such as Web pages) from the client computing devices 102. The content provider 104 can further include an origin server component 112 and associated storage component 114 corresponding to one or more computing devices for obtaining and processing requests for network resources from the CDN service provider. One skilled in the relevant art will appreciate that the content provider 104 can be associated with various additional computing resources, such additional computing devices for administration of content and resources, DNS name servers, and the like. For example, although not illustrated in FIG. 1, the content provider 104 can be associated with one or more DNS name server components that would be authoritative to resolve client computing device DNS queries corresponding to a domain of the content provider.
With continued reference to FIG. 1, the content delivery environment 100 can further include a CDN service provider 106 in communication with the one or more client computing devices 102 and the content providers 104 via the communication network 108. The CDN service provider 106 illustrated in FIG. 1 corresponds to a logical association of one or more computing devices associated with a CDN service provider. Specifically, the CDN service provider 106 can include a number of Point of Presence (herein “POP”) locations 116, 122, 128 that correspond to nodes on the communication network 108. Each POP 116, 122, 128 includes a DNS component 118, 124, 130 made up of a number of DNS server computing devices for resolving DNS queries from the client computers 102. Each POP 116, 122, 128 also includes a resource cache component 120, 126, 132 made up of a number of cache server computing devices for storing resources from content providers and transmitting various requested resources to various client computers. The DNS components 118, 124 and 130 and the resource cache components 120, 126 132 may further include additional software and/or hardware components that facilitate communications including, but not limited to, load balancing or load sharing software/hardware components.
In an illustrative embodiment, the DNS component 118, 124, 130 and resource cache component 120, 126, 132 are considered to be logically grouped, regardless of whether the components, or portions of the components, are physically separate. Additionally, although the POPs 116, 122, 128 are illustrated in FIG. 1 as logically associated with the CDN Provider 106, the POPs will be geographically distributed throughout the communication network 108 in a manner to best serve various demographics of client computing devices 102. Additionally, one skilled in the relevant art will appreciate that the CDN service provider 106 can be associated with various additional computing resources, such as additional computing devices for administration of content and resources, and the like.
With reference now to FIGS. 2-4, one embodiment related to the interaction between various components of the content delivery environment 100 of FIG. 1 will be illustrated. For purposes of the example, however, the illustration has been simplified such that many of the components utilized to facilitate communications are not shown. One skilled in the relevant art will appreciate that such components can be utilized and that additional interactions would accordingly occur without departing from the spirit and scope of the present disclosure.
With reference to FIG. 2, an illustrative interaction for the optional registration of a content provider 104 with the CDN service provider 106 for hosting content on behalf of the content provider 104 will be described. As illustrated in FIG. 2, the CDN service provider content registration process begins with registration of the content provider 104 with the CDN service provider 106. In an illustrative embodiment, the content provider 104 utilizes a registration application program interface (“API”) to register with the CDN service provider 106 such that the CDN service provider 106 can provide content on behalf of the content provider 104, or at least perform the processes described herein. Illustratively, the registration API can include the identification of the origin server 112 of the content provider 104 that may provide requested resources to the CDN service provider 106. In addition or alternatively, the registration API can include the content to be stored by the CDN service provider 106 on behalf of the content provider 104. Additionally, the content provider 104 can specify one or more network storage providers (not illustrated) that may act as an origin server for the content provider 104.
With continued reference to FIG. 2, upon receiving the registration API, the CDN service provider 106 obtains the registration information and generates, or otherwise obtains, embedded resource identifiers that will be utilized in the mapping of client identifiers. In an illustrative embodiment, and as will be explained in greater detail below, the embedded resource identifiers correspond to data or instructions that are processed by the client computing devices 102 to cause the client computing devices 102 to request specific resources from the CDN service provider 106. The resources may correspond to content, such as multi-media content, that is being hosted on behalf of the content provider 104. Additionally, in this illustrative embodiment, the CDN service provider 106 generates, or otherwise obtains, executable code that causes the client computing device to transmit resource requests to one or more computing devices associated with the CDN service provider 106. Unlike requests related to the embedded resource identifiers, the transmission of requests to the CDN service provider 106 based on the execution of the executable code may not result in the transmittal of actual content by the CDN service provider 106.
The CDN service provider 106 returns the resource identifiers and executable code to the content provider 104 along with any additional information. In turn, the content provider 104 can then store the embedded resource identifiers for embedding in requested content or otherwise embed (or associate) the embedded resource identifiers and executable code with requested content (such as Web page markup language). In an illustrative embodiment, the embedded resource identifiers can be applicable to multiple content providers 104. Alternatively, the embedded resource identifiers can be unique to each particular content provider 104. Still further, the CDN service provider 106 may provide additional logic to the content providers 104 that controls the circumstances or methodologies for processing the embedded resource identifiers and executable code provided in the requested content, such as executing the executable code. For example, the embedded resource identifiers can include instructions (or executable code) that defines that the type of content (e.g., specific Web pages) for which the embedded resource identifiers will apply.
With reference now to FIG. 3, after completion of the registration and embedding processes illustrated in FIG. 2, a client computing device 102 generates a content request that is received and processed by the content provider 104, such as through the Web server 110. In accordance with an illustrative embodiment, the request for content can be in accordance with common network protocols, such as the hypertext transfer protocol (“HTTP”). Upon receipt of the content request, the content provider identifies the appropriate responsive content. In an illustrative embodiment, the requested content can correspond to a Web page that is displayed on the client computing device 102 via the processing of information, such as hypertext markup language (“HTML”), extensible markup language (“XML”), and the like.
As previously described, the requested content can include a number of embedded resource identifiers that corresponds to resource objects that should be obtained by the client computing device 102 as part of the processing of the requested content. The embedded resources can corresponds to multi-media content, such as images, videos, text, etc. that will be processed by the client computing devices 102 and rendered on output device. Additionally, the requested content will also include the additional executable code previously provided by the CDN service provider 106 (FIG. 2). In an illustrative embodiment, the embedded executable code previously provided by the CDN service provider 106 can be arranged in a manner such that it is processed prior to processing any other of the content in the requested content or processed in the earlier stages of the processing of the requested content, as allowed. Alternatively, the embedded executable code previously provided by the CDN service provider 106 can also be arranged such that it is processed after all any other embedded resources are processed so as to mitigate any type of interference or delay in the processing of other embedded resources/identifiers. Examples of executable code that can be included in the content requests include scripts executable by a browser software application, stand-alone executable software code, intermediate software code requiring additional processing, and the like.
Generally, the identification of the embedded resources provided by the content provider 104 will be in the form of resource identifiers that can be processed by the client computing device 102, such as through a browser software application. In an illustrative embodiment, the resource identifiers can be in the form of a uniform resource locator (“URL”). For purposes of an illustrative example, the URL can identify a domain of the content provider 104 (e.g., contentprovider.com) or CDN service provider 106 (e.g., CDNserviceprovider), a name of the resource to be requested (e.g., “resource.xxx”) and a path where the resource will be found (e.g., “path”). By way of an illustrative example, the URLs of the embedded resource have the form of:
http://www.contentprovider.com/path/resource.xxx
or
http://www.CDNserviceprovider.com/path/resource.xxx
Additionally, in an illustrative embodiment, any additional embedded resource identifiers previously provided by the CDN service provider 106 during the registration process (FIG. 2) will also be in the form of a resource identifier (e.g., URLs) that can be processed by the client computing device 102, such as through a browser software application. For purposes of an illustrative example, the URL can identify a domain of the CDN service provider 106 (e.g., CDNserviceprovider.com), a name of a resource to be requested (e.g., “resource.xxx”) and a path where the resource will be found (e.g., “path”). As will be explained in greater detail, the additional embedded resource identifiers previously provided by the CDN service provider 106 will identify a special resource such that a request for the special resource may not result in the delivery of an actual resource to the requesting client computing device 102. Accordingly, additional embedded resource identifiers can correspond to a different or the same domain as the other embedded resource identifiers included in the content request. In this illustrative example, the URLs of the additional embedded resource identifiers can have the form of:
http://www.CDNserviceprovider.com/path/resource.xxx
With reference now to FIG. 4A, upon receipt of the requested content, including the embedded resource identifiers and the executable code previously provided by the CDN service provider 106, the client computing device 102 processes the received information in a manner that causes the client computing device 102 to request embedded resource previously provided by the CDN service provider 106 from the CDN service provider 106. In accordance with an embodiment utilizing the hypertext transfer protocol (“HTTP”), the request of a resource can correspond to a GET request transmitted by the client computing device 102 to an IP address associated with CDN service provider 106. Although not illustrated in FIG. 4A, the client computing device 102 would first issue a DNS query for the embedded resource previously provided by the CDN service provider 102, which if properly resolved, would include the identification of the above mentioned IP address associated with the CDN service provider 106. One skilled in the relevant art will appreciate that the resolution of the DNS query may involve multiple DNS queries to either the content provider 104 or CDN service provider 106.
With continued reference to FIG. 4A, the client computing device 102 also processes the executable code, such as a script, that causes the client computing device to generate one or more resource requests, or other types of data exchange between the CDN service provider 106 and the client computing device. In one embodiment, the request of a resource can also correspond to a GET request transmitted by the client computing device 102 to an IP address associated with CDN service provider 106. However, the resulting resource request generated by the client computing device 102 does not have to result in the transmission of the resource from the CDN service provider 106. Upon receipt of the resource request, the receiving POP, POP 116 processes the request and returns a response. Illustratively, the processing of the resource request can include the collection or logging of information associated with the resource request that will allow the CDN service provider 106 to determine performance metric information. The processing of the resource request can also include the generation of identifiers or other information that is returned to the client computing device 102 and that can be collected by the client computing device for purposes of determining performance metric information.
In an illustrative embodiment, based on the execution of the executable code, the client computing device 102 may transmit multiple resource requests for purposes of determining latency information. For example, a client computing device 102 may transmit two resource requests to different POPs to determine latency information associated with each POP. In another example, a client computing device 102 may transmit multiple resource requests to the same POP to verify latency information, conduct a series of latency tests for a single POP, test different software applications on the client computing device 102 or CDN service provider 106, test various Internet Service Provider (“ISP”) functionality, and the like. With reference now to FIG. 4B, the client computing device 102 processes the executable code included in the returned content, such as a script, that causes the client computing device to generate additional resource requests, or other types of data exchange between the CDN service provider 106 and the client computing device. As described above, in one embodiment, the request of a resource can also correspond to a GET request transmitted by the client computing device 102 to an IP address associated with CDN service provider 106. However, the resulting resource request generated by the client computing device 102 may not necessarily correspond to any content that is to be generated by the client computing device and does not have to result in the transmission of resource from the CDN service provider 106. Upon receipt of the resource request, the receiving POP, POP 122, processes the request and, optionally, returns a response. Illustratively, the processing of the resource request can include the collection or logging of information associated with the resource request that will allow the CDN service provider 106 to determine performance metric information. The processing of the resource request can also include the generation of identifiers or other information that is returned to the client computing device 102 and that can be collected by the client computing device for purposes of determining performance metric information.
Finally, with reference now to FIG. 4C, with continued reference to an embodiment in which the executable code results in multiple resource requests to various POPs, the client computing device 102 processes the executable code, such as a script, that causes the client computing device to generate additional resource requests, or other types of data exchange between the CDN service provider 106 and the client computing device. As described above, in one embodiment, the request of a resource can also correspond to a GET request transmitted by the client computing device 102 to an IP address associated with CDN service provider 106. Similar to the description in FIG. 4B, the resulting resource request generated by the client computing device 102 may not necessarily correspond to any content that is to be generated by the client computing device and does not have to result in the transmission of resource from the CDN service provider 106. Upon receipt of the resource request, the receiving POP, POP 128, processes the request and returns a response. Illustratively, the processing of the resource request can include the collection or logging of information associated with the resource request that will allow the CDN service provider 106 to determine performance metric information. The processing of the resource request can also include the generation of identifiers or other information that is returned to the client computing device 102 and that can be collected by the client computing device for purposes of determining performance metric information.
Turning now to FIG. 5, a routine 500 implemented by a client computing device 102 for the generation of resource requests based on the execution of executable code will be described. At block 502, the client computing device 102 transmits the original request for content. As described above, the request for content may directed to a Web server 110 of the content provider 104. At block 504, the client computing device 102 obtains responsive content that includes the embedded executable code provided by the CDN service provider 106 to the content provider 104. As described above, in an illustrative embodiment, the embedded executable code can correspond to script-based instructions that can be processed by a software application running on the client computing device 102. Still further, the translation request code can be organized in the responsive content such that the translation request is the first data processed by the client computing device 102 in accordance with the limitations of the limitations/capabilities of the networking protocols and markup language.
At block 506, the client computing device 102 executes the embedded executable code and, at block 508, transmits a first request for embedded resources to the CDN service provider 106. As previously described, the executable code may be configured such that the resource request transmitted by the client computing device 102 is directed to a specific CDN service provider 106 component. At decision block 510, a test is conducted to determine whether the execution of the executable code results in additional resource requests. If so, the routine 500 returns to block 508 for the generation of one or more additional resource requests. The client computing device 102 can collect and store information associated with the transmission of each resource request and receipt of any response. Additionally, the client computing device 102 can process any returned information that facilitates a determination of performance metric information. For example, the returned information may include timing information, such as a time stamp, that can be utilized to determine network latency between the transmission and receipt of a response from the CDN service provider 106. As previously described, the additional resource requests may be configured such that they are to be received by the POP receiving the first resource request (e.g., a repeat resource request) or by a different POP within the CDN provider's domain.
Returning to decision block 510, once all the resource requests have been transmitted, at block 512, the client computing device 102 can process all collected resource request information to assist in the determination of latencies in the receipt of resources from the various components of the CDN service provider 106. In other embodiments, the processing of resource request information may correspond to the transmission of any collected information to the CDN service provider 106. Illustratively, the executable code provided in the returned content can include logic and functions necessary to process the resource request information and provide it to the CDN service provider 106. Alternatively, the client computing device 102 can include additional executable code or modules, software applications, etc. that facilitate the processing and reporting of the resource request information and provide it to the CDN service provider 106. Additionally, in embodiments in which the CDN service provider 106 obtains all the relevant information upon receipt of the resource request (e.g., embedded timing information it the request), block 512 may be omitted. At block 514, the routine 500 terminates.
With reference now to FIGS. 6-8, another embodiment related to the interaction between various components of the content delivery environment 100 of FIG. 1 will be illustrated. For purposes of this illustrative example, however, the illustration has been simplified such that many of the components utilized to facilitate communications are not shown. One skilled in the relevant art will appreciate that such components can be utilized and that additional interactions would accordingly occur without departing from the spirit and scope of the present disclosure.
With reference now to FIG. 6, after completion of the registration and embedding processes illustrated in FIG. 2, a client computing device 102 generates a content request that is received and processed by the content provider 104, such as through the Web server 110. In accordance with an illustrative embodiment, the request for content can be in accordance with common network protocols, such as HTTP. Upon receipt of the content request, the content provider identifies the appropriate responsive content. As described above, in an illustrative embodiment, the requested content can correspond to a Web page that is displayed on the client computing device 102 via the processing of information, such as HTML, XML, and the like. The requested content can include a number of embedded resource identifiers that corresponds to resource objects that should be obtained by the client computing device 102 as part of the processing of the requested content. The embedded resources can corresponds to multi-media content, such as images, videos, text, etc. that will be processed by the client computing devices 102 and rendered on output device.
As described above, the identification of the embedded resources provided by the content provider 104 will be in the form of resource identifiers that can be processed by the client computing device 102, such as through a browser software application. In an illustrative embodiment, the resource identifiers can be in the form of a URL. For purposes of an illustrative example, the URL can identify a domain of the content provider 104 (e.g., contentprovider.com) or CDN service provider 106 (e.g., CDNserviceprovider), a name of the resource to be requested (e.g., “resource.xxx”) and a path where the resource will be found (e.g., “path”). By way of an illustrative example, the URLs of the embedded resource have the form of:
http://www.contentprovider.com/path/resource.xxx
or
http://www.CDNserviceprovider.com/path/resource.xxx
Additionally, in an illustrative embodiment, the additional embedded resource identifiers previously provided by the CDN service provider 106 during the registration process (FIG. 2) will also be in the form of a resource identifier (e.g., URLs) that can be processed by the client computing device 102, such as through a browser software application. For purposes of an illustrative example, the URL can identify a domain of the CDN service provider 106 (e.g., CDNserviceprovider.com), a name of a resource to be requested (e.g., “resource.xxx”) and a path where the resource will be found (e.g., “path”). As will be explained in greater detail, the embedded resource previously provided by the CDN service provider 106 will identify a special resource such that a request for the special resource may not result in the delivery of an actual resource to the requesting client computing device 102. As previously discussed, the additional embedded resource identifiers can correspond to a different or the same domain as the other embedded resource identifiers included in the content request. In this illustrative example, the URLs of the embedded resource have the form of:
http://www.CDNserviceprovider.com/path/resource.xxx
With reference now to FIG. 7, upon receipt of the requested content, including the embedded resource identifiers and the executable code previously provided by the CDN service provider 106, the client computing device 102 processes the received information in a manner that causes the client computing device 102 to request embedded resource previously provided by the CDN service provider 106 from the CDN service provider 106. In accordance with an embodiment utilizing HTTP, the request of a resource can correspond to a GET request transmitted by the client computing device 102 to an IP address associated with CDN service provider 106. Although not illustrated in FIG. 7, the client computing device 102 would first issue a DNS query for the embedded resource previously provided by the CDN service provider 102, which if properly resolved, would include the identification of the above mentioned IP address associated with the CDN service provider 106. One skilled in the relevant art will appreciate that the resolution of the DNS query may involve multiple DNS queries to either the content provider 104 or CDN service provider 106.
As also illustrated in FIG. 7, a receiving POP, POP 116, obtains the resource request and processes the request. Illustratively, the processing of the resource request can include the collection or logging of information associated with the resource request that will allow the CDN service provider 106 to determine performance metric information. Additionally, in this embodiment, the processing of the resource request also includes the generation of at least one additional resource identifier and corresponding commands that will cause the client computing device 102 to issue one or more subsequent requests for resources. In accordance with an embodiment utilizing HTTP, the response can include a resource identifier in accordance with a REDIRECT command that causes the client computing device 102 to generate a subsequent resource request.
With reference now to FIG. 8, in an illustrative embodiment, upon receipt of the response (e.g., the at least one additional resource identifier and corresponding commands) from the CDN service provider 106, the client computing device 102 issues a subsequent resource response corresponding to the at least one additional resource identifier. In one embodiment, the additional resource identifier is configured such that the subsequent request is received at a different POP, POP 122. In another embodiment, the additional resource identifier can be configured such that the subsequent request is received at the same POP. Based on a series of commands, the client computing device 102 or CDN service provider 106 can collect performance metric information that facilitates the determination of latency information (or other information) associated with the transmission of resource requests.
Turning now to FIG. 9, a routine 900 implemented by a CDN service provider 106 for the processing of resource requests will be described. One skilled in the relevant art will appreciate that actions/steps outlined for routine 900 may be implemented by one or many computing devices/components that are associated with the CDN service provider 106. Accordingly, routine 900 has been logically associated as being generally performed by the CDN service provider 106, and thus the following illustrative embodiments should not be construed as limiting.
At block 902, the CDN service provider 106 obtains the original request for content. As described above, the client computing device 102 transmits the request for content based on one or more embedded resource identifiers. At block 904, the CDN service provider 106 processes the resource request. In an illustrative embodiment, the CDN service provider 106 can utilize a variety of logic in determining how to process resource requests. For example, if the resource request corresponds to an actual resource to be delivered by the CDN service provider 106, the CDN service provider 106 can utilize various criteria to determine which resource requests will result in the delivery of the resource and which resource requests will result in the return of a REDIRECT command. In another example, the CDN service provider 106 can maintain some type of count or other selection mechanism to determine how many REDIRECT commands to provide. In still another example, the CDN service provider 106 can provide REDIRECT commands for all requests for particular resources or all requests from particular types of requesting client computing devices 102 (e.g., all client computing devices associated with a particular ISP). Additionally, the CDN service provider 106 can collect and store information associated with the transmission of each resource request and receipt of any response.
Once the resource request has been processed, at decision block 906, a test is conducted to determine whether there will be additional resource requests that will be processed. If so, the CDN service provider 106 transmits the alternative resource identifier and corresponding REDIRECT command (or similar command) and the routine 900 returns to block 902 to repeat the process for the alternative resource identifier. Accordingly, the routine 900 can be repeated a number of times for a set of successive resource requests and performance metric measures.
Returning to decision block 906, once all the resource requests have been received, at block 910, the CDN service provider 106 can process all collected resource request information to assist in the determination of latencies in the receipt of resources from the various components of the CDN service provider 106. In other embodiments, the processing of resource request information may correspond to the receipt of any collected information and processing information provided by the client computing device 102. At block 912, the routine 900 ends.
With reference now to FIGS. 10 and 11, another embodiment related to the interaction between various components of the content delivery environment 100 of FIG. 1 will be illustrated. For purposes of this illustrative example, however, the illustration has been simplified such that many of the components utilized to facilitate communications are not shown. One skilled in the relevant art will appreciate that such components can be utilized and that additional interactions would accordingly occur without departing from the spirit and scope of the present disclosure.
With reference now to FIG. 10, after completion of the registration and embedding processes illustrated in FIG. 2, a client computing device 102 generates a content request that is received and processed by the content provider 104, such as through the Web server 110. In accordance with an illustrative embodiment, the request for content can be in accordance with common network protocols, such as HTTP. Upon receipt of the content request, the content provider identifies the appropriate responsive content. As described above, in an illustrative embodiment, the requested content can correspond to a Web page that is displayed on the client computing device 102 via the processing of information, such as HTML, XML, and the like. The requested content can include a number of embedded resource identifiers that corresponds to resource objects that should be obtained by the client computing device 102 as part of the processing of the requested content. The embedded resources can correspond to multi-media content, such as images, videos, text, etc. that will be processed by the client computing devices 102 and rendered on output device.
Although not previously discussed, in an illustrative embodiment, the client computing device 102 and the receiving POP, illustratively POP 116, may engage in a number of communication exchanges corresponding to the communication and networking protocols utilized to exchange information and request/receive the received. For example, with regard to an HTTP-based request, the client computing device 102 may first transmit a synchronization command (e.g., a SYNC command) that elicits an acknowledgement from the receiving POP. At that point, the client computing device 102 and POP can establish a communication channel and process the resource request in a manner described above.
As also illustrated in FIG. 10, a receiving POP, POP 116, obtains the resource request and processes the request. Illustratively, the processing of the resource request can include the collection or logging of information associated with the resource request that will allow the CDN service provider 106 to determine performance metric information.
With reference now to FIG. 11, upon the transmission of the response to the CDN service provider 106, the communication channel is typically closed or terminated by the transmission of a termination command, such as a FIN command in HTTP. In this embodiment, the receiving POP does not transmit the termination command. Rather, the POP 116 transmits a request to another CDN service provider 106 POP, such as POP 122, to transmit one or more commands. The POP 122 obtains the request and transmits the protocol commands to the client computing device 102. As illustrated in FIG. 11, the client computing device 102 may transmit additional protocol commands, such as an acknowledgement to the original POP, POP 116, and can include performance metric information related to the latencies associated with the transmission of protocol commands from the other POP. In an illustrative embodiment, client computing device 102 may not be aware that any of the subsequent transmissions originated from another POP. One skilled in the relevant art will appreciate that while this embodiment is illustrated with regard to specific HTTP commands, the present disclosure is not limited to any particular networking or communication protocol or specific commands or type of commands within a networking or communication protocol.
Turning now to FIG. 12, a routine 1200 implemented by a CDN service provider 106 for the processing of resource requests will be described. One skilled in the relevant art will appreciate that actions/steps outlined for routine 1200 may be implemented by one or many computing devices/components that are associated with the CDN service provider 106. Accordingly, routine 1200 has been logically associated as being generally performed by the CDN service provider 106, and thus the following illustrative embodiments should not be construed as limiting
At block 1202, the CDN service provider 106 obtains the original request for content. As described above, the client computing device 102 transmits the request for content based on one or more embedded resource identifiers. At block 1204, the CDN service provider 106 initiates protocol-based interactions related to the establishment of a communication channel and request for resources. Examples of protocol interactions can include various synchronization commands, acknowledgments and the identification of the requests. Additionally, the CDN service provider 106 can collect and store information associated with the transmission of each resource request and receipt of any response.
Once the resource request has been processed, at decision block 1206, a test is conducted to determine whether there will be additional interaction between the POP and the client computing device 102. If so, the routine 1200 returns to block 1204 for additional protocol interactions. Returning to decision block 1206, once no additional interaction is required or the CDN service provider 106 determines that it wants another component to interact with the client computing device 102, at block 1208, the CDN service provider 106 (through the POP) transmits a request to another POP (or other component) to transmit additional protocol communications with the client computing device 102.
At block 1210, the CDN service provider 106 can process all collected resource request information to assist in the determination of latencies in the receipt of resources from the various components of the CDN service provider 106. In other embodiments, the processing of resource request information may correspond to the receipt of any collected information and processing information provided by to the client computing device 102. At block 1212, the routine 1200 ends.
While illustrative embodiments have been disclosed and discussed, one skilled in the relevant art will appreciate that additional or alternative embodiments may be implemented within the spirit and scope of the present invention. Additionally, although many embodiments have been indicated as illustrative, one skilled in the relevant art will appreciate that the illustrative embodiments do not need to be combined or implemented together. As such, some illustrative embodiments do not need to be utilized or implemented in accordance with scope of variations to the present disclosure.
Conditional language, such as, among others, “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements and/or steps. Thus, such conditional language is not generally intended to imply that features, elements and/or steps are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without user input or prompting, whether these features, elements and/or steps are included or are to be performed in any particular embodiment.
Any process descriptions, elements, or blocks in the flow diagrams described herein and/or depicted in the attached figures should be understood as potentially representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps in the process. Alternate implementations are included within the scope of the embodiments described herein in which elements or functions may be deleted, executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those skilled in the art. It will further be appreciated that the data and/or components described above may be stored on a computer-readable medium and loaded into memory of the computing device using a drive mechanism associated with a computer readable storing the computer executable components such as a CD-ROM, DVD-ROM, or network interface further, the component and/or data can be included in a single device or distributed in any manner. Accordingly, general purpose computing devices may be configured to implement the processes, algorithms and methodology of the present disclosure with the processing and/or execution of the various data and/or components described above.
It should be emphasized that many variations and modifications may be made to the above-described embodiments, the elements of which are to be understood as being among other acceptable examples. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the following claims.

## Claims

1. A method comprising:
providing, by a service provider, executable code for generating a set of requests to the service provider to determine latency information for different components of the service provider, wherein the executable code includes instructions for configuring a first request and a second request to determine latency information from the set of requests, wherein the first request is configured to be directed to a first identified component of the service provider at a first IP address and the second request is configured to be directed to a second identified component of the service provider at a second IP address, and wherein the first and second identified components of the service provider are different;
obtaining, by the service provider, the first and second requests from a client computing device at different components of the service provider, wherein each of the first and second requests is generated by the client computing device as a function of having executed the provided executable code and wherein the first request is obtained by the first identified component of the service provider and the second request is obtained by the second identified component of the service provider;
processing, by the service provider, the first and second requests to determine latency information, wherein the processing includes collecting information associated with the respective first and second requests to determine latency information; and
determining, by the service provider, latency information associated with the first and second requests from the client computing device, the latency information corresponding to a communication latency between the client computing device and the first and second identified components of the service provider.

2. The method as recited in claim 1, wherein providing, by the service provider, executable code for generating the set of requests to the service provider includes providing, by the service provider, the executable code to a content provider for embedding in a network resource.

3. The method as recited in claim 1, wherein the executable code corresponds to a script.

4. The method as recited in claim 1 further comprising providing at least one embedded resource identifier corresponding to an additional resource to be provided by the service provider.

5. The method as recited in claim 1, wherein the service provider corresponds to a content delivery network service provider.

6. The method as recited in claim 1, wherein processing at least one of the first and second requests includes providing no resource responsive to the request.

7. The method as recited in claim 1 further comprising providing a response to at least one of the first and second requests transmitted by the client computing device.

8. A computer-implemented system comprising:
a data store for storing performance metric information associated with processing resource requests; and
a computing system in communication with said data store that is operative to:
provide information for generating a series of requests to a service provider to determine latency information for different components of the service provider, wherein the information includes instructions for configuring at least a first request and a second request to determine latency information from the series of requests, wherein the first request is configured to be directed to a first identified component of the service provider at a first IP address and the second request is configured to be directed to a second identified component of the service provider at a second IP address, and wherein the first and second identified components of the service provider are different;
obtain the first and second requests from a client computing device at different components of the service provider, wherein each of the first and second requests is generated by the client computing device having executed the provided instructions and wherein the first request is obtained by the first identified component of the service provider and the second request is obtained by the second identified component of the service provider;
process the first and second requests to determine latency information, wherein the processing includes collecting information associated with the respective first and second requests to determine latency information;
determine latency information associated with each of the first and second requests, wherein the latency information corresponds to a communication latency between the client computing device and the first and second identified components of the service provider; and
update performance metric information according to the latency information.

9. The system as recited in claim 8, wherein the information for generating the series of requests to the service provider corresponds to executable code executable by a software application associated with the client computing device.

10. The system as recited in claim 8, wherein processing each of the first and second requests includes providing no resource responsive to each request.

11. The system as recited in claim 8, wherein processing each of the first and second requests includes providing a resource responsive to each request.

12. The system as recited in claim 8, wherein the information for generating a series of requests to the service provider corresponds to a script.

13. The system as recited in claim 8, wherein the computing system is further operative to provide at least one embedded resource identifier corresponding to an additional resource to be provided by the service provider.

14. The system as recited in claim 8, wherein the computing system determines latency information associated with the first and second requests based on latency information obtained from the client computing device associated with the first and second requests and provided to the computing system responsive to execution of the executable code.

15. A computer-implemented system comprising:
at least one processing device that is operative to:
provide, by a service provider, executable code for generating a set of requests to the service provider to determine latency information for different components of the service provider, wherein the executable code includes instructions for configuring a first request a second request to determine latency information from the set of requests, wherein the first request is configured to be directed to a first identified component of the service provider at a first IP address and the second request is configured to be directed to a second identified component of the service provider at a second IP address, and wherein the first and second identified components of the service provider are different;
obtain, by the service provider, the first and second requests from a client computing device at different components of the service, wherein each of the first and second requests is generated by the client computing device as a function of having executed the provided executable code and wherein the first request is obtained by the first identified component of the service provider and the second request is obtained by the second identified component of the service provider;
process, by the service provider, the first and second requests to determine latency information, wherein the processing includes collecting information associated with the respective first and second requests to determine latency information; and
determine, by the service provider, latency information associated with the first and second requests from the client computing device, the latency information corresponding to a communication latency between the client computing device and the first and second identified components of the service provider.

16. The system as recited in claim 15, wherein providing, by the service provider, executable code for generating the set of requests to the service provider includes providing, by the service provider, the executable code to a content provider for embedding in a network resource.

17. The system as recited in claim 15, wherein the at least one processing device is further operative to provide at least one embedded resource identifier corresponding to an additional resource to be provided by the service provider.

18. The system as recited in claim 15, wherein processing at least one of the first and second requests includes providing no resource responsive to the request.

19. The system as recited in claim 15, wherein the at least one processing device is further operative to provide a response to at least one of the first and second requests transmitted by the client computing device.