IBM Support

IT31495: SHARED MEMORY SEGMENTS LEFT BEHIND IF SECONDARY GOES DOWN BECAUSE OF CONFIG MISMATCH WITH PAIRED SERVER

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APAR status

  • Closed as program error.

Error description

  • When the connection between a primary and secondary is
    established, a certain set of onconfig parameters are checked
    for matching values on either side.  Should a mismatch be
    detected, the secondary will shutdown with a message similar to:
    
    
    DR: Configuration parameter values of the paired servers do not
    match:
                  Parameter: LOGBUFF
                  Current server's value: 1024
                  Paired  server's value: 512
                  The parameter values must match.
    DR:Shutting down the server.
    DR:Terminating the master daemon to bring system down
    immediately.
    
    The problem is that, after correcting the parameter mismatch,
    the secondary server will fail to start due to issues with
    creation of the shared memory. The online log will show messages
    of the form:
    
    IBM Informix Dynamic Server Started.
    Requested shared memory segment size rounded from 2812KB to
    3280KB
    shmget: [EEXIST][17]: key 52a84801: shared memory already exists
    mt_shm_init: can't create resident segment
    
    Running the onstat command will show:
    
    *** WARNING: IBM Informix Dynamic Server is no longer running.
    ***
    
    *** WARNING: IBM Informix Dynamic Server is no longer running.
    ***
    
    This problem is the result of the previous server shutdown not
    removing all of the shared memory segments.
    

Local fix

  • Running the command "onmode -ky" or "onclean -ky" should remove
    the shared memory segments and allow for the server to be
    restarted.
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * Users of Informix Server prior to 12.10.xC14 and 14.10.xC4.  *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See Error Description                                        *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Update to Informix Server 12.10.xC14 or 14.10.xC4 (when      *
    * available).                                                  *
    ****************************************************************
    

Problem conclusion

  • Fixed in Informix Server 12.10.xC14 and 14.10.xC4.
    

Temporary fix

Comments

APAR Information

  • APAR number

    IT31495

  • Reported component name

    INFORMIX SERVER

  • Reported component ID

    5725A3900

  • Reported release

    C10

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2020-01-13

  • Closed date

    2020-03-03

  • Last modified date

    2020-03-03

  • 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

    INFORMIX SERVER

  • Fixed component ID

    5725A3900

Applicable component levels

[{"Business Unit":{"code":"BU048","label":"IBM Software"},"Product":{"code":"SSGU8G","label":"Informix Servers"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"C10","Edition":"","Line of Business":{"code":"","label":""}}]

Document Information

Modified date:
03 March 2020