IT18197: MQ client application suffers memory exception inside MQCONNX

APAR status

• Closed as program error.

Error description

• A multithreaded client application using sharing conversation
  ends unexpectedly within an MQCONNX call.  The call either ends
  abnormally and produces a Failure Data Capture (FDC) record, or
  it returns error code  2594 (MQRC_PASSWORD_PROTECTION_ERROR) on
  a channel which had previously allowed connections.
  
  If an FDC record is produced then it will contain the following
  information:
  
  Probe Id :- XC130031 or XC130003
  Component :- xehExceptionHandler
  Probe Description :- AMQ6109: An internal WebSphere MQ error has
  occurred.
  Comment1          :- Access Violation at address 428 when
  reading
  +--------------------------------------------------------------+
  MQM Function Stack
  MQCTL
  zstMQCTL
  zstMQCTLCommon
  zstAsyncConsume
  zstUserCallback
  zstConsumerFunction
  MQCONNX
  MQCONNX
  trmzstMQCONNX
  reqDoConnect
  reqConnectChl
  rriInitSess
  xcsFFST
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  Applications using message consumer functions registered via
  MQCB calls, which when called are capable of making new MQ
  client connections using MQCONNX.
  
  
  Platforms affected:
  MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  Low level routines within MQ were keeping a count of the times
  initialization had been done for client or non-client
  connections.  An initialization counter for a thread-nonspecific
  data block was being kept in a thread-specific area of MQ's
  data.  Under a specific scenario, it was possible for the
  counter to have an incorrect value, leading to a data block
  being empty when it was expected to be initialized.
  

Problem conclusion

• The IBM MQ code has been corrected.  The counter for the
  thread-nonspecific data block is kept in a thread-nonspecific
  area.  This prevents the issue from arising.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v8.0       8.0.0.7
  v9.0 CD    9.0.3
  v9.0 LTS   9.0.0.2
  
  The latest available maintenance can be obtained from
  'WebSphere MQ Recommended Fixes'
  http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006037
  
  If the maintenance level is not yet available information on
  its planned availability can be found in 'WebSphere MQ
  Planned Maintenance Release Dates'
  http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006309
  ---------------------------------------------------------------
  

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

  WMQ BASE MULTIP

• Fixed component ID

  5724H7251

Applicable component levels