IBM Support

IT04083: WEBSPHERE MQ R531.10 ON NSS QUEUE SERVERS MAY RECEIVE RC30 IF THEY ARE IN A COMPLEX ENVIRONMENT USING MQGMO_SET_SIGNAL

Subscribe

You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • Fixpack 10 for WebSphere MQ r531 for Non Stop Server, NSS,
    attempted to increase the Message Quick Cell, "MQC's", limit for
    MQ processes. Message Quick Cell, "MQC's", are a system resource
    that are used to deliver messages (I-O). By default a limit of
    1023 is set for all processes by the operating system.  This
    results in additional processing to obtain more when needed.
    This would be avoided by having a larger upper limit from the
    outset. Increasing this limit does not affect processes, it only
    allows additional "MQC's" to be used, if they are needed.
    In a large queue manager more than 1023 "MQC's" may be required.
    When MQ attempts to use more than 1023 "MQC's" the Queue Server
    receives a return code 30.  Error 30 = Message system is unable
    to obtain memory because either no entry is available in the
    message block pool or the maximum number of RECEIVE or SEND
    message blocks are already in use.
    

Local fix

  • Set the MQQSCONTROLSEND PARAM in the Pathway Queue Server
    serverclass to a value between the default value 1023 and 4079.
    Any value in this range will work around this issue.
    

Problem summary

  • Fixpack 10 for WebSphere MQ r531 for Non Stop Server, NSS,
    attempted to increase the Message Quick Cell, "MQC's", limit fo
    MQ processes. Message Quick Cell, "MQC's", are a system resourc
    that are used to deliver messages (I-O). By default a limit of
    1023 is set for all processes by the operating system.  This
    results in additional processing to obtain more when needed.
    This would be avoided by having a larger upper limit from the
    outset. Increasing this limit does not affect processes, it onl
    allows additional "MQC's" to be used, if they are needed.
    In a large queue manager more than 1023 "MQC's" may be required
    When MQ attempts to use more than 1023 "MQC's" the Queue Server
    receives a return code 30.  Error 30 = Message system is unable
    to obtain memory because either no entry is available in the
    message block pool or the maximum number of RECEIVE or SEND
    message blocks are already in use.
    

Problem conclusion

  • The Queue Server has been changed to call GPC
    CONTROLMESSAGESYSTEM to set the maximum limit on the number of
    outstanding messages sent by the process to 4000.
    

Temporary fix

  • Set the MQQSCONTROLSEND PARAM in the Pathway Queue Server
    serverclass to a value between the default value 1023 and 4079.
    Any value in this range will work around this issue.
    

Comments

APAR Information

  • APAR number

    IT04083

  • 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

    2014-08-28

  • Closed date

    2015-02-23

  • Last modified date

    2016-06-13

  • 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

[{"Line of Business":{"code":"LOB36","label":"IBM Automation"},"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSFKSJ","label":"WebSphere MQ"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"5.3.1"}]

Document Information

Modified date:
17 November 2020