International Business Machines Corporation

Gabriel Garcia Montero

Brian Keith Martin

Srinivas Hasti

Aditya Abhay Desai

Jason Robert McGee

David B Colasurdo

Nataraj Nagaratnam

Gennaro A Cuomo

Michael L Fraenkel

Kevin Edward Vaughan

Renganathan Sundararaman

Aravind Srinivasan

Elias N Bayeh

Robert C Will

Gautam Singh

Charles Plilip Fricano

A dynamic rebalancer operates in a server cluster independently of routers directing traffic to the servers in the cluster. An analysis component uses configuration information and statistics information to determine which session, if any, should be moved. A filter component receives transfer instructions from the analysis component. When the filter component receives transfer instructions from the analysis component, the filter component adds a redirect command to the client request. The filter component continually redirects client requests within the session to the new server until the client receives the redirect command and begins to send client requests to the new server.

Method and system for dynamically rebalancing client sessions within a cluster of servers connected to a network

A dynamic topic partitioning messaging system. The messaging system can include a message server; one or more topics stored in the message server; one or more subtopics associated with at least one of the topics in the message server; and, a dynamic topic partitioning system configured to partition the topics into the subtopics. Notably, the message server can be Java message service (JMS) compliant. In that regard, the message server can reside in a single process address space. For example, the process address space can be a Java virtual machine (JVM).

Dynamic partitioning of messaging system topics

Prioritization of fragmented messages in an ORB is achieved by intercepting the flow of message data within the ORB, marking the current data stream location and issuing sufficient read commands to gather the message header and control area information. Then classification for priority can be performed using the data in the control area to classify the request. The classification information is stored for the message for later use by queuing and prioritization processes and the data stream marker is reset to the original location. When the queuing and prioritization processes are ready to dispatch the message, the message can be sent on to the higher levels of processing within the ORB where the higher levels of message processing code will process the message, totally unaware of the fact that the message has been classified and/or queued or prioritized prior to delivery to the higher level.

Method and program for classifying fragmented messages

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.

Voting mechanism for session invalidation processing in an application server cluster

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. The identification of the second server and the first session is received at the HTTP routing server and communications associated with the first session are routed from the HTTP routing server to the second server responsive to receiving the identification of the second server so that backup session state information maintained at the second server is used to continue the first session from the first server at the second server.

Dynamically updating session state affinity

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. If no match is found, the request is dispatched to a server clone in the server group using any reasonable Work Load Management (WLM) mechanism and then the clone identification code of the selected clone is added to the list.

Method and apparatus for maintaining session affinity across multiple server groups

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.

Method and apparatus for scheduling invalidation tests for HTTP sessions

A method and apparatus for securing hypertext transfer protocol sessions authenticates a user's credentials before creating a session. The present invention then associates the session with the credentials. Subsequent requests are submitted with the session ID and the user credentials to be associated with the session. Therefore, an unauthorized user that has obtained a session ID cannot gain access to sensitive content associated with the session without possessing the valid credentials.

Method and apparatus for securing session information of users in a web application server environment

A technique, system, and computer program for maintaining session information among multiple clustered computers for servlets and providing those servlets with various session services. The session services are implemented using a plug-in servlet engine. The session information is preferably maintained without using a persistent data store, to avoid performance penalties associated with storing information in persistent storage such as a database. A locking technique is implemented to prevent servlets from inadvertently overwriting each other's session object data. A registration process is preferably used, to optimize communication of configuration property changes. Non-proprietary interfaces are used, allowing for scalability, portability, and maximum industry acceptance of this solution.

Growing community of inventors

Chapel Hill, NC, United States of America

Gabriel Garcia Montero