Group Management Service

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 are aware of the failure and can take action when failure occurs. Many features of Application Server depend upon GMS. For example, GMS is used by the IIOP failover, in-memory replication, transaction service, and timer service features.

If server instances in a cluster are located on different machines, ensure that the machines are on the same subnet.

The GMS feature is not available in the developer profile. In the cluster profile and the enterprise profile, GMS is enabled by default.

GMS is a core service of the Shoal framework. For more information about Shoal, visit the Project Shoal home page.

To Enable or Disable GMS for a Cluster

1. In the tree component, select Clusters.

2. Click the name of the cluster.

3. Under General Information, ensure that the Heartbeat Enabled checkbox is checked or unchecked as required.

   • To enable GMS, ensure that the Heartbeat Enabled checkbox is checked.

   • To disable GMS, ensure that the Heartbeat Enabled checkbox is unchecked.

4. If you are enabling GMS and require different values for these defaults, change the default port and IP address for GMS.

5. Click Save.

Configuring GMS

Configure GMS for your environment by changing the settings that determine how frequently GMS checks for failures. For example, you can change the timeout between failure detection attempts, the number of retries on a suspected failed member, or the timeout when checking for members of a cluster.

To configure monitoring in the Admin Console, go to Application Server node –> Configuration –> Group Management Service.

The equivalent asadmin commands are get and set.