PI08162: SVRCONN CHLS WITH SHARECNV > 0 MAY NOT INVOKE EXITS AND STORAGE LEAK MAY OCCUR IN SP 0 KEY 8 XSTB

Obtain the fix for this APAR.

APAR status

• Closed as unreproducible.

Error description

• WMQ z/OS Storage leak when processing exits.
  When running with SHARECNV(0) there is a 104 byte
  block allocated for passing parameters to the
  exit.
  When the channel terminates, this storage is freed,
  but with a non-zero SHARECNV channels (SHARECNV > 0),
  the storage is not correctly freed when a conversation
  ends.
  .
  These 104 byte blocks will never be freed, causing long
  storage chains and increasing CPU during future
  storage allocation operations.
  .
  Level2 Verification Steps:
  ip %mqvsmdc 0 8
  .
  LIST 30319000. LENGTH(X'00002000') ASID(X'0254') AR
    Addr   Offs  x'1B8' Allocated from Beginning
  30319000 +0000 E7220018 E7E2E3C2 000000A8 FFFFFFFF
  30319010 +0010 FFFFFFFF 00000000 00000001 00000001
  30319020 +0020 40404040 40404040 40404040 40404040
  30319030 +0030 40404040 40404040 40404040 40404040
  .
  EA
   -----EBCDIC----- -----ASCII------
  *X...XSTB...y....*."..............*
  *................*................*
  *                *@@@@@@@@@@@@@@@@*
  *                *@@@@@@@@@@@@@@@@*
  .
  #2 By which repeating Storage-Block size takes up the
  most total storage
  ( total used by this SP/KEY =    116412416 )
  size-dec    size-hex #found   total-storage-used
  ----------- -------- -------- ------------
      1052672   101000       23     24211456
        36864     9000      192      7077888
      2105344   202000        3      6316032
      3158016   303000        2      6316032
         8192     2000      614      5029888  <= XSTB
         4096     1000      850      3481600
        12288     3000      274      3366912
        73728    12000       42      3096576
  ..
  24 hours later
  ..
  ip %mqvsmdc 0 8
  .
   #2 By which repeating Storage-Block size takes up the
   most total storage
  ( total used by this SP/KEY =    123867136 )
  size-dec    size-hex #found   total-storage-used
  ----------- -------- -------- ------------
      1052672   101000       15     15790080
      3158016   303000        3      9474048
        36864     9000      210      7741440
      2105344   202000        3      6316032
         8192     2000      753      6168576 <= XSTB
      5263360   505000        1      5263360
         4096     1000     1057      4329472
        12288     3000      313      3846144
  .
  Additional Symptom(s) Search Keyword(s):
  High CPU in CHIN
  .
  SHARECNV = 1
  SHARECNV = 10
  SHARECNV(10)
  .
  ADDITIONAL KEYWORDS:
  SP0 KEY8
  

Local fix

• Need to recycle CHIN periodically.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of WebSphere MQ for z/OS Version 7 *
  *                 Release 0 Modification 1                     *
  ****************************************************************
  * PROBLEM DESCRIPTION: Exits for SVRCONN channels may not be   *
  *                      correctly invoked for all conversations *
  *                      on a channel when the SHARECNV channel  *
  *                      attribute is greater than 1.            *
  *                                                              *
  *                      Additionally, when using exits on a     *
  *                      SVRCONN channel where the SHARECNV      *
  *                      channel attribute is greater than one,  *
  *                      a storage leak may occur each time a    *
  *                      new conversation is started on a        *
  *                      channel.                                *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  When a new conversation is started on an active channel,
  attributes relating to exits are not correctly copied to the new
  conversation. This prevents the exits from being invoked and
  can result in a storage leak when starting conversations.
  

Problem conclusion

Temporary fix

Comments

• Processing has been amended to ensure that the correct
  information relating to exits is copied to subsequent
  conversations.
  

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

  UI14520

Modules/Macros

• CSQXRMSS
  

Fix information

• Fixed component name

  WMQ Z/OS V7

• Fixed component ID

  5655R3600

Applicable component levels

• R010 PSY UI14520

     UP14/03/04 P F403

Fix is available

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