Alert monitor

The alert monitor transaction, CKAM, handles unscheduled events--known as pending events--that occur as a result of connect requests to instances of WebSphere MQ. The alert monitor generates messages that are sent to the system console.

There are two kinds of pending events:

1. Deferred connection

If CICS tries to connect to WebSphere MQ before the queue manager is started, a pending event called a deferred connection is activated. When the queue manager is started, a connection request is issued by the CICS adapter, a connection is made, and the pending event is canceled.

There can be multiple deferred connections, one of which will be connected when the queue manager is started.

2. Termination notification

When a connection is successfully made to WebSphere MQ, a pending event called termination notification is created. This pending event expires when:

• The queue manager shuts down normally with MODE(QUIESCE). The alert monitor issues a quiesce request on the connection.

• The queue manager shuts down with MODE(FORCE) or terminates abnormally. After an abnormal termination, the CICS adapter waits for ten seconds and then tries a connect call. This enables the CICS system to be automatically reconnected to the queue manager when the latter is restarted.

• The connection is shut down from the CKQC transaction.

The maximum number of pending events that CICScan handle is 99. If this limit is reached, no more events can be created until at least one current event expires.

The alert monitor terminates itself when all pending events have expired. It is subsequently restarted automatically by any new connect request.