What is the ARM?

The z/OS Automatic Restart Manager (ARM) is a z/OS recovery function that can improve the availability of your queue managers. When a job or task fails, or the system on which it is running fails, ARM can restart the job or task without operator intervention.

If a queue manager or a channel initiator has failed, ARM restarts it on the same z/OS image. If z/OS, and hence a whole group of related subsystems and applications have failed, ARM can restart all the failed systems automatically, in a predefined order, on another z/OS image within the sysplex. This is called a cross-system restart.

The channel initiator should be restarted by ARM only in exceptional circumstances. If the queue manager is restarted by ARM, you should restart the channel initiator from the CSQINP2 initialization data set (see Using ARM in a WebSphere MQ network).

We can use ARM to restart a queue manager on a different z/OS image within the sysplex in the event of z/OS failure. The network implications of WebSphere MQ ARM restart on a different z/OS image are discussed in Using ARM in a WebSphere MQ network.

To enable automatic restart:

• Set up an ARM couple data set.

• Define the automatic restart actions that you want z/OS to perform in an ARM policy.

• Start the ARM policy.

Also, WebSphere MQ must register with ARM at startup (this happens automatically).

Note:

If you want to restart queue managers in different z/OS images automatically, define every queue manager as a subsystem in each z/OS image on which that queue manager might be restarted, with a sysplex wide unique 4-character subsystem name.