Chapter 30. High Availability Using Server Hinting

In Red Hat JBoss Data Grid, Server Hinting ensures that backed up copies of data are not stored on the same physical server, rack, or data center as the original. Server Hinting does not apply to total replication because total replication mandates complete replicas on every server, rack, and data center.
Data distribution across nodes is controlled by the Consistent Hashing mechanism. JBoss Data Grid offers a pluggable policy to specify the consistent hashing algorithm. For details see Section 30.4, “ConsistentHashFactories”
Setting a machineId, rackId, or siteId in the transport configuration will trigger the use of TopologyAwareConsistentHashFactory, which is the equivalent of the DefaultConsistentHashFactory with Server Hinting enabled.
Server Hinting is particularly important when ensuring the high availability of your JBoss Data Grid implementation.

30.1. Establishing Server Hinting with JGroups

When setting up a clustered environment in Red Hat JBoss Data Grid, Server Hinting is configured when establishing JGroups configuration.
JBoss Data Grid ships with several JGroups files pre-configured for clustered mode. These files can be used as a starting point when configuring Server Hinting in JBoss Data Grid.