IT19592: WMQ FOR HP NONSTOP SERVER: APPLICATIONS MAY RECEIVE THE ERROR MQRC_STORAGE_NOT_AVAILABLE ON MQCONN CALLS.

WebSphere MQ for HP NonStop Server V5.3.1 fix pack 5.3.1.14

APAR status

• Closed as program error.

Error description

• After a long period of time of the queue manager being active
  and if there are a lot of mqconn/mqdisc, applications may no
  longer be able to connect to the queue manager and may receive
  the following error: MQRC=2071 (MQRC_STORAGE_NOT_AVAILABLE).
  

Local fix

• Restart the queue manager.
  

Problem summary

•  For each task opening the shared ipcc subpool
  the process information is added to the connectors list, when
  the task does not cleanly detach from the shared ipcc subpool,
  the quickcell containing this information isn't freed.
  Normally the subpool subtask should regularly check and free
  those quickcells, due to the cpu local nature of shared memory
  on NonStop, the subpool subtask won't work as intended and was
  therefore removed.
  This leads to continuously leaking quickcells when applications
  do not call mqdisc for each mqconn, eating up the preallocated
  heap space in shared ipcc subpool, once all heap space is filled
  up with quickcells the next mqconn would require allocating a
  new extend for the shared ipcc subpool, this requires the
  current process to be executed by a member of mqm group,
  otherwise this is delegated to the, non-existing,
  subpool subtask.
  Due to this extending the shared ipcc subpool fails,
  leading to the observed 2071 reason code on mqconn.
  

Problem conclusion

•  Existing connectors list cleanup function
  was made available throughout common services domain, to be
  called before allocating a new chunk of quickcells from
  heap space, to avoid unnecessary extension of connectors list.
  

Temporary fix

•  Call mqdisc before applications terminate
  and avoid terminating processes connected to the queue manager.
  

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  WEBS MQ NSS ITA

• Fixed component ID

  5724A3902

Applicable component levels