PI48282: WMQ Z/OS: THE MQ LISTENER STOPS WHEN PI10617 IS IMPLEMENTED WITHOUT THE PROPER TCPCONFIG SETTINGS TO ALLOW 2MB BUFFERS.

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• CHISERVP was set with the value to implement PI10617 and allow
  2MB TCP/IP buffers. After the CHINs were restarted the LISTENER
  immediately stopped without any error messages explaining why:
  
  CSQX251I CSQXSTRL Listener started, TRPTYPE=TCP INDISP=QMGR
  CSQX023I CSQXLSTT Listener started,
   port <port> address *
   TRPTYPE=TCP INDISP=QMGR
  CSQX234I CSQXLSTT Listener stopped, TRPTYPE=TCP INDISP=QMGR
  
  
  The listener could not be dynamically started:
  CSQM134I CSQMSLIS START LISTENER TRPTYPE(TCP) COMMAND ACCEPTED
  CSQX017I CSQXSTRL Listener already started,
   port <port> address *,
   TRPTYPE=TCP INDISP=QMGR
  CSQ9023E CSQXCRPS ' START LISTENER' ABNORMAL COMPLETION
  
  STOPping and STARTing the LISTENER did not help. Recycling the
  CHIN did not help.
  
  When CHISERVP was set to its previous value, the listener stayed
  running.
  
  Additional Symptom(s) Search Keyword(s):
  2M 2 MB service parameter
  

Local fix

• PI10617 requires that TCP/IP maximum Send/Recv buffer sizes are
  configured so that the CHINIT will be able to set the requested
  2MB buffer. This needs to be done with the following settings
  in the TCPCONFIG:
  
  TCPMAXSNDBUFRSIZE 2048K
  TCPMAXRCVBUFRSUZE 2048K
  
  Note that these do not set the default buffer sizes for
  applications (e.g. MQ); they just allow applications to request
  buffers up to the specified size.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of WebSphere MQ for z/OS Version 7 *
  *                 Release 1 Modification 0.                    *
  ****************************************************************
  * PROBLEM DESCRIPTION: When using the mechanisms provided by   *
  *                      APARs PI10617 and PM71966 to increase   *
  *                      the TCP/IP send or receive buffer       *
  *                      sizes, customers may find that their    *
  *                      listeners terminate with message        *
  *                      CSQX234I and cannot be restarted        *
  *                      without recycling the channel initiator *
  *                      address space.                          *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  When using the mechanisms provided by APARs PM71966 and PI10617
  to increase the TCP/IP buffer sizes, if a size is requested that
  exceeds the system-wide limit (as configured with
  TCPMAXSNDBUFRSIZE or TCPMAXRCVBUFRSIZE), then the listener will
  terminate immediately and cannot be restarted until the channel
  initiator address space is recycled.
  

Problem conclusion

• Processing has been amended to ensure that a failure to set a
  larger TCP/IP buffer size than permitted by the current system
  configuration does not result in the listener task terminating.
  100Y
  CSQXCLIT
  

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:

  PI48766 UI32501

Modules/Macros

• CSQXCLIT
  

Fix information

• Fixed component name

  WMQ Z/OS V7

• Fixed component ID

  5655R3600

Applicable component levels

• R100 PSY UI32501

     UP15/12/15 P F512

Fix is available

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