Communications stopped

TCP

If TCP is stopped for some reason and then restarted, the WebSphere MQ for z/OS TCP listener waiting on a TCP port is stopped.

Automatic channel reconnect allows the channel initiator to detect that TCP/IP is not available and to automatically restart the TCP/IP listener when TCP/IP returns. This alleviates the need for operations staff to notice the problem with TCP/IP and manually restart the listener. While the listener is out of action, the channel initiator can also be used to retry the listener at the interval specified by LSTRTMR in the channel initiator parameter module. These attempts can continue until TCP/IP returns and the listener successfully restarts automatically. For information about LSTRTMR, see the WebSphere MQ for z/OS System Setup Guide.

LU6.2

If APPC is stopped, the listener is also stopped. Again, in this case, the listener automatically retries at the LSTRTMR interval so that, if APPC restarts, the listener can restart too.

If the DB2(R) fails, shared channels that are already running continue to run, but any new channel start requests will fail. When the DB2 is restored new requests are able to complete.