Removing idle tpipes

IMS scans transaction pipes (tpipes) during system checkpoint processing to determine if any tpipes can be deleted.

IMS removes transaction pipes after they have been idle for three consecutive system checkpoints, except in the following circumstances:
  • Commit-then-send messages are queued on the tpipe or the tpipe hold queue.
  • The tpipe is stopped.
  • A trace is set on the tpipe.
  • The tpipe is a synchronized tpipe, such as a tpipe used by MQSeries® for commit-then-send input transactions.
  • The tpipe is in a WAIT state for a resume tpipe request that specified either the AUTO or the SINGLE-WAIT options.
  • The tpipe is in an MCP state, which indicates that the tpipe is running in a shared queues environment and might have output messages on the global queue.
    Tip: If no messages are queued to the TPIPE but the MCP status is displayed for the TPIPE so that the tpipe cannot be removed, issue the /DISPLAY TMEMBER tmembername TPIPE tpipename QCNT command or the /DISPLAY TMEMBER tmembername QCNT command to reset the MCP status.
  • The tpipe is being scanned by IMS.

You can use the /DISPLAY TMEMBER TPIPE command to see whether a tpipe cannot be removed by IMS because one of the circumstances in the preceding list is true for the tpipe.

If IMS cannot remove a tpipe that has been idle across three consecutive checkpoints because one of the circumstances in the preceding list is true, IMS attempts to remove the idle tpipe again at the following system checkpoint.

You can view information about OTMA clients, OTMA tpipe connections, and the OTMA messages that are currently being processed by IMS by issuing the type-2 IMS command QUERY OTMATI.