The Group Management Service (GMS) is an infrastructure component that is enabled for the instances in a cluster. When GMS is enabled, if a clustered instance fails, the cluster and the Domain Administration Server (DAS) are notified of the failure and can respond to the failure. The following features depend on GMS:
IIOP failover
In-memory replication
Transaction service
Timer service
For information about using GMS, see the following topics: