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

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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 number

    IT19592

  • Reported component name

    WEBS MQ NSS ITA

  • Reported component ID

    5724A3902

  • Reported release

    531

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2017-03-08

  • Closed date

    2017-03-14

  • Last modified date

    2017-03-14

  • 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

[{"Business Unit":{"code":"BU048","label":"IBM Software"},"Product":{"code":"SSCPQ5M","label":"APAR"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"5.3.1","Edition":"","Line of Business":{"code":"","label":""}}]

Document Information

Modified date:
14 March 2017