Memory-to-memory replication
Memory-to-memory replication uses the data replication service to replicate data across many appservers in a cluster without using a database. Using this method, sessions are stored in the memory of an appserver, providing the same functionality as a database for session persistence. Separate threads handle this functionality within an existing appserver process.
The data replication service is an internal WAS component. In addition to its use by the session manager, it is also used to replicate dynamic cache data and stateful session beans across many appservers in a cluster.
The advantages of using this method of session persistence are:
- Flexible configuration options, such as peer-peer and client/server
- Elimination of the overhead and cost of setting up and maintaining a real-time production database.
- Elimination of single point of failure that can occur with a database.
- Encrypted session information between appservers.