Expert Advice

NAS_AA_DB2_QPctFull  
Situation Description
Suggested Actions
Situation Description

This situation is triggered when the queue percent full as determined by the DB2 apply server has reached a warning level. The queue percent full is the fullness of the queue as a percentage.

The Queue Percent Full attribute is displayed in the Queue Apply: Receive Queue Details table view and the Queue Percent Full circular gauge view of the DB2 Replication Details workspace.

 

Suggested Actions

The queue percent full may be higher than expected due to the following conditions:

  • Replication is restarted and there is a large amount of pending source updates to be processed. The queue percent full should return to a normal level when the backlog is processed.
  • The occurrence of a peak update period. The queue percent full should return to a normal level when the number of source updates to be processed has dropped and the servers have a chance to catch up.
  • The apply cache is too small.

Possible user actions are:

  • Utilize the IBM InfoSphere Replication Server Q Replication Dashboard to identify and troubleshoot problems related to programs, queues, Q subscriptions, and other objects. From the Queues tab, you can view health statistics for each send queue and receive queue, including fullness of queues by number of messages or percentage of the maximum fullness (queue depth).
  • You may to want run the ASNMON(QAPPLY_QDEPTH) task to monitor related alert conditions.
  • Check the STATE_INFO and STATE fields in the IBMQREP_RECVQUEUES table to determine the state of the queue. You may want to set an alert condition for queue inactive (RECEIVE QUEUES ALL INACTIVE) to alert in case the queue is stopped.
  • You may want to tune some of the counters in the IBMQREP_RECVQUEUES table in order to increase processing of the Apply queue. For example, the values of the MEM_FULL_TIME and APPLY_SLEEP_TIME fields in the IBMQREP_APPLYMON table may indicate that some tuning is needed for the values of the MEMORY_LIMIT and NUM_APPLY_AGENTS fields in the IBMQREP_RECVQUEUES table. See the Q replication tuning section in the IBM Information Management Software for z/OS Solutions Information Center or DB2 Information Center for more details.
  • If necessary, issue STOPQ (e.g. F CAPjob,STOPQ=QDECODERXMLL1) at the capture side, so that Apply will have a chance to process the messages after the condition has been corrected and issue STARTQ (e.g. F CAPjob,STARTQ=QDECODERXMLL1) at Capture.

 

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