Session
Management System
Purpose
To answer the needs of business scenarios where several concurrent users work with multiple applications, the architecture of AS Java provides central session management. The session management system, represented by the Session manager, is responsible for enhanced control of sessions lifecycle and mechanisms for session failover in case of a server failure.
Features
In general, sessions are used to keep the state of a user accessing an application between several requests.
The session management system provides:
● Common administration and monitoring of session state
Every Java instance has a common shared memory area where server processes and the ICM store all their monitoring information (sessions, processes, EJBs and so on), which can be used for detailed analysis of the current internal status.
● Flexible session failover
Session failover is used to improve the robustness of AS Java. The approach is based on the idea of separating active sessions from inactive sessions and keeping all important sessions in an independent safe storage. The AS Java offers three kinds of storage for inactive sessions: database, file system and shared memory.
Shared memory based failover provides the best performance of the three. It is enabled by the use of SAP’s implementation of a Java Virtual Machine – SAP JVM.
All server processes in the instance have access to a shared memory region used as a session store, which is not damaged if a server failure occurs due to certain problems such as out-of-memory errors, JVM bugs, and so on. All the saved sessions are then loaded into a different server process and the user remains unaffected by the crash.
More
information:
Java
Instance
Activities
● You can monitor sessions (their state, size, user, start time, storage and so on) using the SAP Management Console.
More information: Monitoring the Application Server with the SAP MC
● You can configure the properties of the Session Manager, including session failover and monitoring shared memory using the Config Tool.
More information: