Monitor queues

Use this page to view tasks that help you to resolve a problem with a queue and the application that services that queue. Various monitoring options are available to determine the problem

Frequently, the first sign of a problem with a queue that is being serviced is that the number of messages on the queue (CURDEPTH) increases. If you expect an increase at certain times of day or under certain workloads, an increasing number of messages might not indicate a problem. However, if you have no explanation for the increasing number of messages, you might want to investigate the cause.

We might have an application queue where there is a problem with the application, or a transmission queue where there is a problem with the channel. Additional monitoring options are available when the application that services the queue is a channel.

The following examples investigate problems with a particular queue, called Q1, and describe the fields that you look at in the output of various commands:

• Determining whether the application has the queue open
  If we have a problem with a queue, check whether the application has the queue open
• Check that messages on the queue are available
  If we have a large number of messages on the queue and the application is not processing any of those messages, check whether the messages on the queue are available to the application
• Check whether the application is getting messages off the queue
  If we have a problem with a queue and the application that services that queue, check whether the application is getting messages off the queue
• Determining whether the application can process messages fast enough
  If messages are building up on the queue, but your other checks have not found any processing problems, check that the application can process messages fast enough. If the application is a channel, check that the channel can process messages fast enough.
• Check the queue when the current depth is not increasing
  Even if the current depth of our queue is not increasing, it might still be useful to monitor the queue to check whether the application is processing messages correctly.

Parent topic: Real-time monitoring