IV43442: Five minute hang then connection-broken on JMS client channel caused by error in the queue manager SVRCONN channel

Fix Pack 7.1.0.4 for WebSphere MQ V7.1
WebSphere MQ V7.5 Fix Pack 7.5.0.3

APAR status

• Closed as program error.

Error description

• A queue manager had a CCSID of 932, and a WebSphere MQ JMS
  client was connecting to it.  A non-existent SVRCONN channel
  name was supplied by the user.  The server-side channel program
  failed to handle fully the initial handshaking with the client.
  The server-side channel program should have sent response data
  to the client indicating that the channel name was incorrect,
  but instead it incorrectly waited for more data from the client.
  This caused a 5 minute period where nothing happened, because
  all this time the client was waiting for a response from the
  server.  The experience of the end user is similar to a hang.
  

Local fix

• Apply the ifix
  

Problem summary

• ****************************************************************
  USERS AFFECTED:
  Users of WebSphere MQ clients in extremely rare error scenarios
  during initial handshaking.
  
  Platforms affected:
  All Distributed (iSeries, all Unix and Windows)
  ****************************************************************
  PROBLEM SUMMARY:
  The server-side channel program code executing in this scenario
  did not check a return code from a failing internal function.
  But that return code should have been checked.
  

Problem conclusion

• The WebSphere MQ product code has been corrected so that it
  checks the internal return code, and takes appropriate action
  if it indicates failure.
  
  The same code fix was made earlier on z/OS under APAR PM79595.
  This is therefore a port of that fix, but the symptoms in this
  APAR are a separate and different symptom from that seen on
  z/OS.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
                     v7.1
  Platform           Fix Pack 7.1.0.4
  --------           --------------------
  Windows            7.1.0.4
  AIX                7.1.0.4
  HP-UX (Itanium)    7.1.0.4
  Solaris (SPARC)    7.1.0.4
  Solaris (x86-64)   7.1.0.4
  iSeries            7.1.0.4
  Linux (x86)        7.1.0.4
  Linux (x86-64)     7.1.0.4
  Linux (zSeries)    7.1.0.4
  Linux (Power)      7.1.0.4
  
  Platform           v7.5
  --------           --------------------
  Multiplatforms     7.5.0.3
  
  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 AIX V7

• Fixed component ID

  5724H7221

Applicable component levels

• R710 PSY

     UP