Abstract: An admission control system for a server including an admission controller that receives a stream of messages from one or more clients targeted for the server. The admission controller relays to the server the messages in the stream that correspond to a number of sessions already underway between the clients and the server. The admission controller also relays to the server the messages in the stream that do not correspond to sessions already underway if a hybrid and predictive admission control strategy using information provided by a resource monitor indicates that additional sessions can be handled by the server. The admission controller defers the messages otherwise.

Abstract: A method comprises distributing a plurality of descriptors of file encoded with comprising a plurality of recipient nodes, wherein at least one descriptor is distributed from the first node to each recipient node of the at least a portion of the first group. The at least a portion of the first group communicate their respective descriptors received from the first node to other nodes of the first group. A system comprises an origin node operable to distribute all of a plurality of descriptors of a MDC file to a first group of recipient nodes, wherein the origin node does not attempt to communicate all of the plurality of descriptors to all of the recipient nodes of the first group. The recipient nodes of the first group are each operable to communicate a descriptor that it receives from the origin node to other nodes of the first group.

Abstract: In accordance with one embodiment, a method of distributing a file from a first node to a plurality of recipient nodes comprises partitioning a file F into a plurality of subfiles. The method further comprises performing distribution of the file F to a plurality of recipient nodes using a distribution technique that comprises (a) attempting to distribute the plurality of subfiles from a first node to a first group of recipient nodes, and (b) the plurality of recipient nodes of the first group attempting to exchange their respective subfiles received from the first node. The method further comprises detecting a failed node, and the distribution technique adapting to distribute the file F to each non-failed node of the plurality of recipient nodes.

Abstract: A method of distributing a file from a first node to a plurality of recipient nodes comprises logically organizing a plurality of recipient nodes to which a file is to be distributed into a plurality of groups of recipient nodes. The file is distributed to the plurality of groups, wherein the distributing includes (a) partitioning the file into a plurality of subfiles, (b) distributing the plurality of subfiles from a first node to a first group, wherein at least one subfile is distributed from the first node to each recipient node of the first group but not all of the plurality of subfiles are distributed from the first node to any of the recipient nodes of the first group, and (c) the plurality of recipient nodes of the first group exchanging their respective subfiles such that each recipient node of the first group obtains all of the plurality of subfiles.

Abstract: A system and method for distributing a file from a first node to a plurality of recipient nodes are provided. The method comprises partitioning a file into a plurality of subfiles, and distributing the plurality of subfiles from a first node to a first group comprising a plurality of recipient nodes, wherein at least one subfile is distributed from the first node to each recipient node of the first group but not all of the plurality of subfiles are distributed from the first node to any of the recipient nodes of the first group. The method further comprises the plurality of recipient nodes of the first group exchanging their respective subfiles such that each recipient node of the first group obtains all of the plurality of subfiles.

Abstract: A method of distributing a file from a first node to a plurality of recipient nodes comprises logically organizing a plurality of recipient nodes to which a file is to be distributed into a plurality of groups of recipient nodes. The file is partitioned into a plurality of subfiles. The file is distributed to a plurality of recipient nodes using a distribution technique comprising (a) an origin node attempting to communicate the plurality of subfiles to recipient nodes of the first group, (b) the plurality of recipient nodes of the first group attempting to exchange their respective subfiles received from the origin node, and (c) attempting to distribute the plurality of subfiles from at least one node of the first group to recipient nodes of a second group. The method further comprises detecting a failed node, and the distribution technique adapting to distribute the file to each non-failed node.

Abstract: In one embodiment of the present invention, a method for measuring the capacity of a media server for supporting concurrent media streams to a population of clients is provided. The method comprises identifying a mixed workload, wherein the mixed workload corresponds to a number of media streams served concurrently by the media server to a population of clients wherein all of said number of media streams do not comprise common content encoded at a common bit rate. The method further comprises using a cost function to compute a load for the media server under the mixed workload.

Abstract: According to one embodiment of the present invention, a method is provided for measuring performance of service provided to a client by a server in a client-server network. The method comprises capturing network-level information for a client access of data from a server in a client-server network, wherein the client-server network comprises a server side and a client side and wherein the network-level information is captured on the server side. The method further comprises determining from the captured network-level information at least one performance measurement relating to the client access of data.

Abstract: According to one embodiment of the present invention, a method for compiling desired information for network transactions is provided. The method comprises capturing network-level information in a kernel-level module of a processor-based device arranged on the server-side of a client-server communication network, and using the captured network-level information to compile, in the kernel-level module, desired information for at least one network transaction conducted between a client and a server via the client-server communication network. Another embodiment of the present invention provides a method for compiling desired information for network transactions that comprises implementing a kernel-level module in a STREAMS-based network stack of a server, wherein the kernel-level module is operable to monitor a network connection to the server to compile desired information for network transactions conducted through the network connection.

Abstract: According to one embodiment of the present invention, a method for reconstructing client web page accesses is provided that comprises capturing network-level information for client accesses of at least one web page, and using the captured network-level information to reconstruct client accesses of the at least one web page. Another embodiment of the present invention provides a method for reconstructing client information accesses. The method comprises capturing network-level information for client accesses of information from a server, wherein each client access of the information comprises a plurality of transactions. The method further comprises relating the plurality of transactions to their corresponding client access of information from the server.

Abstract: According to one embodiment of the present invention, a method for reconstructing client web page accesses is provided that comprises capturing network-level information for client accesses of at least one web page. The method further comprises constructing a knowledge base of reliable information identifying content of at least one web page, and reconstructing at least one client web page access from the captured network-level information using the reliable information of the knowledge base.

Abstract: A method for determining the priority of documents in a web cache. The present invention incorporates the document size and the frequency of file access in determining which documents to keep in the cache and which documents to replace. The priority of a document is determined using a ratio of the frequency of access of the document raised to a first value to the size of the document raised to a second value, wherein the first value and the second value are rational numbers other than one. In one embodiment, the first value is greater than one and the second value is less than one. In another embodiment, the age of the document is also considered in determining the priority of a document. In the present embodiment, the ratio is added to a clock value, wherein the clock value is a running counter associated with the document starting at the time the document was first stored in the web cache.

Abstract: A method and system for workload-aware request in cluster-based network servers. The present invention provides a web server cluster having a plurality of nodes wherein each node comprises a distributor component, a dispatcher component and a server component. In another embodiment, the present provides a method for managing request distribution to a set of files stored on a web server cluster. A request for a file is received at a first node of a plurality of nodes, each node comprising a distributor component, a dispatcher component and a server component. If the request is for a core file, the request is processed at the first node (e.g., processed locally). If the request is for a partitioned file, it is determined whether the request is assigned to be processed locally at the first node or at another node (e.g., processed remotely). If the request is for neither a core file nor a partitioned file, the request is processed at the first node.

Abstract: One embodiment of the present invention provides a method for detecting client aborted connections from web access logs produced by web servers. The present embodiment utilizes the following two fields of the logs: the requested web document name and the number of bytes transferred by the web server of that requested document. Specifically, the present embodiment first determines the real size of the web document from the log information. Once determined, if another transferred bytes value is less than the real size, the document was either modified or the client aborted the connection. The present embodiment filters out the document modifications from the aborted connections by relying on the assumption that modifications to a document generate one change in transferred bytes followed by the same size for a time while an aborted connection will manifest itself as a one time change in the number of transferred bytes.

Abstract: A method and system for handing-off TCP states in a communication network. Specifically, the present invention allows for handing-off TCP states between nodes in an associated network that is optimized for rare handoff of TCP states. The handoff occurs between dynamically loadable modules that wrap around the TCP/IP stack located at a front-end node and a selected back-end web server. A handoff protocol implemented by the loadable modules works within the kernel level of the existing TCP/IP code. As such, no changes to the existing TCP/IP code is necessary. The loadable modules at the front-end are able to select a back-end web server depending on the content of the web request, coordinate handing off TCP states, and forward packets to the back-end web server. Loadable modules at the selected back-end modify response packets going out to reflect the proper TCP state of the front-end node.

Abstract: A method and system for handing-off TCP states in a communication network. Specifically, the present invention discloses allows for transferring TCP states between front-end node and a plurality of back-end web servers. The handoff occurs between dynamically loadable modules that wrap around the TCP/IP stack located at a front-end node and a selected back-end web server. A handoff protocol implemented by the loadable modules works within the kernel level of the existing TCP/IP code. As such, no changes to the existing TCP/IP code is necessary. The loadable modules at the front-end are able to select a back-end web server depending on the HTTP request, coordinate handing off TCP states, and forward packets to the back-end web server. Loadable modules at the selected back-end modify response packets going out to reflect the proper TCP state of the front-end node.

Abstract: A method and system for handing-off TCP states in a communication network. Specifically, the present invention allows for handing-off TCP states between nodes in an associated network that is optimized for frequent handoff of TCP states. The handoff occurs between dynamically loadable modules that wrap around the TCP/IP stack located at a front-end server and a selected back-end server. A handoff protocol implemented by the loadable modules works within the kernel level of the existing TCP/IP code. As such, no changes to the existing TCP/IP code is necessary. The loadable modules at the front-end are able to select a back-end server depending on the content of the HTTP request, coordinate handing off TCP states, and forward packets to the back-end server. Loadable modules at the selected back-end modify response packets to reflect the proper TCP state of the front-end server.

Abstract: A method for determining the priority of documents in a web cache. The present invention incorporates the document size and the frequency of file access in determining which documents to keep in the cache and which documents to replace. The priority of a document is determined using a ratio of the frequency of access of the document raised to a first value to the size of the document raised to a second value, wherein the first value and the second value are rational numbers other than one. In one embodiment, the first value is greater than one and the second value is less than one. In another embodiment, the age of the document is also considered in determining the priority of a document. In the present embodiment, the ratio is added to a clock value, wherein the clock value is a running counter associated with the document starting at the time the document was first stored in the web cache.

Abstract: A method and system for caching objects and replacing cached objects in an object-transfer environment maintain a dynamic indicator (Pr(f)) for each cached object, with the dynamic indicator being responsive to the frequency of requests for the object and being indicative of the time of storing the cached object relative to storing other cached objects. In a preferred embodiment, the size of the object is also a factor in determining the dynamic indicator of the object. In the most preferred embodiment, the cost of obtaining the object is also a factor. A count of the frequency of requests and the use of the relative time of storage counterbalance each other with respect to maintaining a cached object in local cache. That is, a high frequency of requests favors maintaining the object in cache, but a long period of cache favors evicting the object. Thus, cache pollution is less likely to occur.

Abstract: An admission control system for a server including an admission controller that receives a stream of messages from one or more clients targeted for the server. The admission controller relays to the server the messages in the stream that correspond to a number of sessions already underway between the clients and the server. The admission controller also relays to the server the messages in the stream that do not correspond to sessions already underway if a hybrid and predictive admission control strategy using information provided by a resource monitor indicates that additional sessions can be handled by the server. The admission controller defers the messages otherwise.