PQ61319: GROWTH OF 32K CSM DATASPACE AFTER STOPPING AND RESTARTING TCPIP

Obtain the fix for this APAR.

APAR status

• Closed as unreproducible.

Error description

• Customer saw a growth in CSM FIXED storage usage after stopping
  and restarting TCPIP.  The growth was in the 32K dataspace
  buffers. The buffers contained TCPIP datagrams.
  (MV23094)
  
  Verification Steps:
  1) Obtain dump after stopping TCPIP
      -Dump should contain CSM and CSM Dataspace
  2) Use VERBX VTAMMAP 'CSMPOOL CSMTYPE() CSMSIZE()' to determine
     if the growth is in 32K dataspace buffers.
  3) Run VERBX VTAMMAP 'CSMOWNER CSMOWNID(vtamasid)' to see if
     the majority of the 32K dataspace buffers belong to VTAM
     and show up as _image_buffers.
  4)Look at some of the buffers and they will contain TCPIP
     datagrams.
     (MV23094)
  .
  ADDITIONAL SYMPTOMS:
  

Local fix

• KEYWORDS: 32K DATASPACE CSM STOP TCPIP STOPPING RESTART PACKING
            BUFFERS MV23094
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of the IBM Communications Server   *
  *                 for OS/390 Release 10 IP: restarting TCPIP   *
  ****************************************************************
  * PROBLEM DESCRIPTION: 32K CSM dataspace growth after TCPIP is *
  *                      stopped and restarted                   *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  In certain cases the 32K CSM dataspace packing buffers will not
  be freed when recycling the TCPIP tasks.  These buffers may
  contain TCPIP datagrams.
  +-------------------------------------------------------------+
  + Please check our Communications Server for OS/390 homepages +
  + for common networking tips and fixes.  The URL for these    +
  + homepages can be found in Informational APAR II11334.       +
  +-------------------------------------------------------------+
  

Problem conclusion

Temporary fix

Comments

• The TCPIP EOM logic in the IF layer has been amended to free
  the 32K dataspace packing buffers.
  

APAR Information

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

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

  UQ66702

Modules/Macros

• EZBIFEOM
  

Fix information

• Fixed component name

  TCP/IP V3 MVS

• Fixed component ID

  5655HAL00

Applicable component levels

• R50A PSY UQ66702

     UP02/06/17 P F206

Fix is available

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