Abstract: Extensible URI-pattern-based servlet request processing frameworks process and respond to requests for resources sent over a network by client programs to application programs in multi-tiered data processing systems. An extension processor component, an improved web container; and an improved web application architecture form the framework. The extension processor component includes one or more extension processor factories, each of which generates a single type of extension processor to handle specific application components. Each extension processor is adapted to respond to a request having a declared pattern. The extension processor factory resides within the web container and provides a list of patterns for which it is responsible. The extension factory also instantiates an extension processor to respond to a request having a pattern that matches that extension processor's declared pattern.

Abstract: Session state affinity is maintained in a workload balancing system that includes a hypertext transfer protocol (HTTP) routing server and a plurality of application servers. The application servers maintain backup session state information for a first session to a first server of the plurality of application servers at fewer than all of the plurality of application servers, detect the unavailability of the first application server at an application server of the plurality of application servers other than the first application and determine a second server that continues the first session. An identification of the second server and the first session is sent from an application server of the plurality of application servers to a HTTP routing server responsive to detecting the unavailability of the first server.

Abstract: Under the present invention, there is provided a voting mechanism for assigning an application server of an application server cluster the task of invalidating all sessions containing listeners in the cluster for a web application. A method for session invalidation processing comprises assigning a vote to a web application upon launch of the web application in an application server of the application server cluster, broadcasting the vote to other application servers of the application server cluster, receiving a vote for the web application from each of the other application servers in the application server cluster in which the web application has been launched, and assigning invalidation processing to the application server containing the web application having the highest vote. The votes are dynamically updated upon the removal or addition of an application server from/to the application server cluster.

Abstract: Under the present invention, a session is established between a user system and an existing version of a network application. Once the session is established, session information corresponding to the session is determined and then communicated to the user system. The session information typically includes a version identifier that identifies the existing version of the network application. Requests received during the same session are accompanied with the session information. The session information is used to route the requests to the existing version of the network application.

Abstract: A clone managed session affinity system, method and apparatus. A clone-managed session affinity method can include receiving a request from a client. The request can include a reference to a selected clone with which the client has a session affinity relationship. The clone can determine whether a session affinity cancellation condition has arisen. If the clone determines that a session affinity termination condition has arisen, the session affinity relationship can be cancelled.

Abstract: The invention is a method and apparatus for maintaining session affinity within a server farm when requests sharing a session ID switch between server groups or between server clones in a single server group. In accordance with the invention, client requests include a list of clone identification codes, each code uniquely identifying a clone within a server group for handling the request. The clone identification code may be appended to a session identification code. For each different server that handles a request in a session, a new clone identification code is appended without deleting or overwriting any previously appended clone identification codes. When a request is received, the list of clone identification codes associated with the request is parsed in a predetermined order to search for the first clone identification code that matches one of the clone identification codes of a server in the appropriate server group. If a match is detected, the request is dispatched to that clone.

Abstract: The invention is a method and apparatus for invalidating session data stored in a database. In accordance with the invention, http sessions stored in the database are allowed to remain in the database without real time testing for session time out. Instead, invalid (or timed out) sessions remain in the database until a specified time. At that specified time, all http sessions are invalidated without actually testing them for time out. Alternately, each session can be individually tested for time out and only those sessions which have actually timed out are removed from the database or otherwise invalidated.

Abstract: The invention and apparatus for updating a back-end database for storing http session for access by multiple servers in a server farm in which the number of writes by the servers to the database are minimized. Particularly, each server maintains up to date copy of the http session data for each http session and writes the http session data to the back-end http session database that is accessible by all of the associated servers only at predetermined intervals. The intervals may be dictated on a purely time basis. Alternately, the interval may be after a specified number of requests are received in a given session or a specified number of changes are made to the http session data of the particular session.