Restrictions of Liberty JVM servers in collectives

Liberty JVM servers can be part of a collective as either a controller or member. Because the Liberty server is embedded in CICS®, some collective operations and features are restricted for Liberty JVM servers.

Liberty JVM servers must be started by using CICS commands

Collectives can control the state of member Liberty servers in the collective using the ServerCommandsMBean MBean.

A CICS Liberty JVM server that joins a collective must not be started by using the ServerCommandsMBean startServer method. Starting a Liberty JVM server with the ServerCommandsMBean runs the Liberty server outside of the CICS address space.

To start a Liberty JVM server, use the SET JVMSERVER command. For more information about controlling a JVM server in CICS, see JVMSERVER resources.

Liberty JVM servers cannot be members of a collective scaling controller

The scalingController-1.0 feature enables automatic scaling of member Liberty servers in a collective and supports two usage scenarios.
  1. JVM elasticity, where the controller starts and stops existing member Liberty servers.
  2. Liberty elasticity, where the controller provisions new member Liberty servers onto registered hosts.
Neither scenario is supported in CICS Liberty JVM servers.

Liberty JVM servers cannot be restarted by using health management policies

The healthManager-1.0 feature provides several health actions that can be run on members of a collective. Health actions are run when a certain health policy is met. For more information, see Configuring health management for Liberty.

One of the health actions that can be run is the restartServer action.

<action action="restartServer"/>

Running the restartServer health action on CICS Liberty JVM servers is not supported.