Memory-to-memory replication
Memory-to-memory session replication is the replication of sessions to another WAS appserver, addressing HTTP Session single point of failure. In a clustered environment, session affinity in the WAS plug-in routes the requests for a given session to the same server.
peer-to-peer cluster Hot failover causes the plug-in to failover to a server that has a backup copy of the session. client/server cluster Server retrieves the session from a server that has the backup copy of the session. For client/server there are three possible modes...
Server Store backup copies of other WAS sessions. Do not to send out copies of sessions owned by the server. Client Send out copies of the sessions owned by server. Do not to receive backup copies of sessions from other servers Both Send out copies of the sessions owned by server. Act as a backup for sessions owned by other servers. The default is both.
Configure all session managers connected to a replication domain to have the same topology. If one session manager instance in a domain is configured to use the client/server topology, then the rest of the session manager instances in that domain must be a combination of servers configured as Client only and Server only. If one session manager instance is configured to use the peer-to-peer topology, then all session manager instances must be configured as Both client and server.
Memory-to-memory replication is accomplished by the creation of a data replication service (DRS) instance in an appserver that talks to other DRS instances in remote appservers.
DRS instances on disparate appservers that replicate to one another must be configured as a part of the same replication domain.
For example, a server only DRS instance and a both client and server DRS instance cannot exist in the same replication domain.
With respect to mode, the following are the primary examples of memory-to-memory replication configuration:
Although the console allows flexibility and additional possibilities for memory-to-memory replication configuration, only the configurations provided above are officially supported.
There is a single replica in a cluster by default. You can modify the number of replicas through the replication domain.
Sub-topics
Memory-to-memory topology: Peer-to-peer function
Memory-to-memory topology: Client/server function
Related concepts
Replication
Related tasks
Replicating data with a multi-broker replication domain