PH38786: IMS CONNECT DELDUMMY CLIENT CREATED EVEN WITH THE CANCEL CLIENT ID OPTION (CANCID) ON.

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• In a IMS 15 IMS connect environment a DELDUMMY Client hang
  condition results from 2 Clients trying to use the same
  ClientId.
  Message 'HWSS0742W MESSAGE FAILED, ORIGIN=xxx yyyy TO DESTID=zzz
  ; R=8, S=DUPECLNT, M=SRE4' is sent and the DELDUMMY Client can
  be seen hanging in the output of a QRY IMSCON TYPE(CLIENT)
  NAME(DELDUMMY) SHOW(ALL) command.
  
  The Cancel Client ID option (CANCID) to terminate the old
  session and replace it with the new one, failed to complete the
  termination of the old Client.
  Under certain circumstances the timestamp of the old client
  stored in CVB field CVB_TARGTIME doesn't match the timestamp in
  SVT field SVT_TIMESTAMP and this causes module HWSSOCM0 to skip
  the call to module HWSSCCM0 to complete Client termination
  process.
  

Local fix

• No Local FIX.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * All IMS 15 IMS Connect OTMA users.                           *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * IMS Connect Cancel Client option does not cancel the         *
  * existing client, and results in an additional DELDUMMY       *
  * client.                                                      *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * INSTALL CORRECTIVE SERVICE FOR APAR/PTF                      *
  ****************************************************************
  An IMS Connect OTMA client attempted to connect to IMS Connect
  (ICON) with the Cancel Client ID option (CANCID).  The client
  already had an existing session on the same IMS Connect port, so
  the CANCID option was supposed to terminate the old session and
  replace it with the new one.
  
  The new session was initially assigned a clientid of DELDUMMY.
  The new session initiated 'stop-client' processing, and module
  HWSSSTP0 created a termination thread (HWSSOCM0) to tear down
  the existing session's connection.  The new session then waited
  for the termination process to complete, expecting to be posted
  by the HWSSOCM0 thread.
  
  The termination process includes validation of the SVT_TIMESTAMP
  field, designed to prevent terminating the existing session if
  it had already been terminated.  However, in this case, the
  existing client thread had processed input or output in
  parallel, and had updated the SVT_TIMESTAMP field.  When
  HWSSOCM0 validated SVT_TIMESTAMP, it detected the change and
  quit processing, because it assumed that the existing session
  must have already terminated.  The result was that the existing
  session was still active, and the new DELDUMMY session was still
  waiting for the existing session to terminate.
  

Problem conclusion

• HWSSSTP0, HWSSOCM0, and HWSSU030 have been modified to use
  SVT_LTOKEN instead of SVT_TIMESTAMP for validation.  SVT_LTOKEN
  is static for the life of the client connection so it won't
  change for input/output being processed in parallel.
  

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:

  UI77947

Modules/Macros

• HWSSU030 HWSSOCM0 HWSSSTP0
  

Fix information

• Fixed component name

  IMS V15

• Fixed component ID

  5635A0600

Applicable component levels

• R500 PSY UI77947

     UP21/11/06 P F111

Fix is available

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