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

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 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