When a network error occurs, the cluster might be partitioned into several different partitions. JGroups has a MERGE service that allows the coordinators in partitions to communicate with each other and form a single cluster back again. The flow control service is configured in the MERGE2 sub-element under the JGroups Config element. Here is an example configuration.
<MERGE2 max_interval="10000"
min_interval="2000"/>
The configurable attributes in the FC element are as follows.
max_interval specifies the maximum number of milliseconds to send out a MERGE message.
min_interval specifies the minimum number of milliseconds to send out a MERGE message.
JGroups chooses a random value between min_interval and max_interval to send out the MERGE message.
The cluster states are not merged in a merger. This has to be done by the application.