The session replication
manager that is
shipped with WebSphere® eXtreme Scale can
work with the default session manager in WebSphere Application Server. Session data is replicated
from one process to another process to support user session data high
availability.
The session manager has been designed so that it can run in any Java™ Platform, Enterprise Edition Version 6 or later container. Because the session manager does not have any dependencies on WebSphere APIs, it can support various versions of WebSphere Application Server, as well as vendor application server environments.
The HTTP session manager provides session replication capabilities for an associated application. The session replication manager works with the session manager for the web container. Together, the session manager and web container create HTTP sessions and manage the life cycles of HTTP sessions that are associated with the application. These life cycle management activities include: the invalidation of sessions based on a timeout or an explicit servlet or JavaServer Pages (JSP) call and the invocation of session listeners that are associated with the session or the web application. The session manager persists its sessions in a fully replicated, clustered and partitioned data grid. The use of the WebSphere eXtreme Scale session manager enables the session manager to provide HTTP session failover support when application servers are shut down or end unexpectedly. The session manager can also work in environments that do not support affinity, when affinity is not enforced by a load balancer tier that sprays requests to the application server tier.
The session replication manager uses a session listener to listen on the changes of session data. The session replication manager persists the session data into an ObjectGrid instance either locally or remotely. You can add the session listener and servlet filter to every web module in your application with tooling that ships with WebSphere eXtreme Scale. You can also manually add these listeners and filters to the web deployment descriptor of your application.
This session replication manager works with each vendor web container session manager to replicate session data across Java virtual machines. When the original server dies, users can retrieve session data from other servers.
eXtreme Scale automatically starts an embedded ObjectGrid container inside any application-server process when the web container initializes the session listener or servlet filter, if the objectGridType property is set to EMBEDDED. See Servlet context initialization parameters for details.
You are not required to package an ObjectGrid.xml file and objectGridDeployment.xml file into your web application WAR or EAR file. The default ObjectGrid.xml and objectGridDeployment.xml files are packaged in the product JAR file. Dynamic maps are created for various web application contexts by default. Static eXtreme Scale maps continue to be supported.
This approach for starting embedded ObjectGrid containers applies to any type of application server. The approaches involving a WebSphere Application Server component or WebSphere Application Server Community Edition GBean are deprecated.