Persistence Servers and Clusters

A persistence server is a process that implements one or more persistence stores. Several servers can cooperate in a persistence cluster.

The servers within the cluster communicate among themselves to replicate message data and acknowledgment data. Replication ensures that the cluster can continue to deliver messages to subscribers, even when some of the servers are unavailable.

Administrators define clusters and their servers within the realm. You can define any number of clusters in the realm. A cluster consists of a set of persistence servers.

A cluster as a whole maintains a set of persistence stores, replicating their data among its servers for fault tolerance.

To ensure the benefits of in-memory replication and fault-tolerant service, each server of a cluster must run on a dedicated host computer.