Switching a stopped cluster-sender channel to another cluster transmission queue
If you choose to make changes manually, you make the changes to a cluster-sender channel when it is stopped and switch it from one cluster transmission queue to another before the cluster-sender channel starts.
Before starting
We might make some configuration changes, and now want to make them effective without starting the cluster-sender channels that are affected. Alternatively, you make the configuration changes you require as one of the steps in the task.
If you reduce the number of messages the switching process has to transfer to the new transmission queue, switching completes more quickly. Read How the process to switch cluster-sender channel to a different transmission queue works for the reasons for trying to empty the transmission queue before proceeding any further.
About this task
This task switches the transmission queues served by stopped or inactive cluster-sender channels. We might do this task because a cluster-sender channel is stopped, and we want to switch its transmission queue immediately. For example, for some reason a cluster-sender channel is not starting, or has some other configuration problem. To resolve the problem, you decide to create a cluster-sender channel, and associate the transmission queue for the old cluster-sender channel with the new cluster-sender channel you defined.
A more likely scenario is we want to control when reconfiguration of cluster transmission queues is performed. To fully control the reconfiguration, you stop the channels, change the configuration, and then switch the transmission queues.
Procedure
- Stop the channels that you intend to switch
- Stop any running or inactive channels that you intend to switch. Stopping an inactive cluster-sender channel prevents it starting while we are making configuration changes.
STOP CHANNEL(ChannelName) MODE(QUIESCSE) STATUS(STOPPED)
- Optional: Make the configuration changes.
For example, see Clustering: Example configuration of multiple cluster transmission queues.
- Switch the cluster-sender channels to the new cluster transmission queues. On Multiplatforms, issue the following command:
runswchl -m QmgrName -c ChannelNameOn z/OS, use the SWITCH function of the CSQUTIL command to switch the messages or monitor what is happening. Use the following command.SWITCH CHANNEL(channel_name) MOVEMSGS(YES)For more information, see SWITCH function.The runswchl, or CSQUTIL SWITCH, command transfers any messages on the old transmission queue to the new transmission queue. When the number of messages on the old transmission queue for this channel reaches zero, the switch is completed. The command is synchronous. The command writes progress messages to the window during the switching process.
During the transfer phase existing and new messages destined for the cluster-sender channel are transferred in order to the new transmission queue.
Because the cluster-sender channel is stopped, the messages build up on the new transmission queue. Contrast the stopped cluster-sender channel, to step 2 in Switching active cluster-sender channels to another set of cluster-transmission queues. In that step, the cluster-sender channel is running, so messages do not necessarily build up on the new transmission queue.
- Optional: Monitor the channels as they switch In a different command window, display the transmission queue depth during the switch. The following example display the status for system cluster transmission queues.
DISPLAY QUEUE('SYSTEM.CLUSTER.TRANSMIT.*') CURDEPTH- Optional: Monitor the messages AMQ7341 The transmission queue for channel ChannelName switched from queue QueueName to QueueName that are written to the queue manager error log.
- Restart the cluster-sender channels that you stopped.
The channels do not start automatically, as you stopped them, placing them into STOPPED status.
START CHANNEL(ChannelName)Parent topic: Clustering: Switching cluster transmission queues
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