PQ60983: ESQA OR ECSA IS EXHAUSTED DUE TO MANY SUSPENDED SRBS FOR TCPIP DUE TO LOCK CONTENTION ON THE IPMAIN LOCK

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• ESQA (SP239) and/or ECSA (SP241) becomes exhausted due to
  many suspended SRBs ( SSRB ) and DUCBs.  The cause
  of the storage growth is due to contention on the IPMAIN lock.
  The DUCB causing the back up for the IPMAIN is suspended
  due to an unconditional request for CSM storage that is
  not available.
  The unconditional storage request came from module
  EZBIFIND - AllocateIpaMpcControl2
  

Local fix

• KEYWORDS:  SSRB SSRBs DUCB SP239 SP241 K6 subpool239 239
  subpool241 key6 SQA ESQA CSM IPMAIN EZBIFIND x'f6000' f6000
  ABEND878 ABEND4C5 2500 PTR MV23837
  .
  VERIFICATION STEPS:
  - ESQA or ECSA storage is exhausted
  - IP TCPIPCS LOCK shows contention on the IPMAIN lock
  - Run the DUAF report ( IP TCPIPCS DUAF ) and locate
    the DUCB identified as holding IPMAIN lock
  - The calling module sequence should look similar to
    the following:
  DUAF report on OMPROUTE DUCB (x'23F0B000') shows it is suspended
  10000C47 24C2DA58 23F0B000 23F0B100 00E3CC80 0149 OMPROUTE 00000
  RSA  23F0B438  Prev 2BD7C0D0  Next 23F0B580  Mod EZBPFCLS  IU SU
  RSA  23F0B588  Prev 23F0B438  Next 23F0B7C0  Mod EZBPFCLO
  RSA  23F0B7C8  Prev 23F0B588  Next 23F0BB70  Mod EZBRWSTR
  RSA  23F0BB78  Prev 23F0B7C8  Next 23F0BF40  Mod EZBIPSPI
  RSA  23F0BF48  Prev 23F0BB78  Next 23F0C6D0  Mod EZBIFIND
  RSA  23F0C6D8  Prev 23F0BF48  Next 23F0CA30  Mod EZBITSCS
  RSA  23F0CA38  Prev 23F0C6D8  Next 00000000  Mod EZBITDSS
  - Module EZBITSCS is called by EZBIFIND to unconditionally
    request CSM storage.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of the IBM Communications Server   *
  *                 for OS/390 Release 10 IP:                    *
  *                 LCS & QDIO Devices                           *
  ****************************************************************
  * PROBLEM DESCRIPTION: Numerous suspended SRBs during period   *
  *                      of critical CSM constraint.             *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  An unconditional storage request during the processing of device
  layer control information left the IPMAIN lock held shared
  indefinitely. This occurred while the system was experiencing
  critical CSM constraint and resulted in many suspended SRBs for
  processes waiting on the IPMAIN lock.
  +-------------------------------------------------------------+
  + 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

• The storage requests have been changed to conditional.
  
  * Cross Reference between External and Internal Names
  

Temporary fix

Comments

APAR Information

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

  PQ58403

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

  UQ66690

Modules/Macros

• EZBIFIND EZBIFIUM EZBIFIUT EZBIPEPR EZBIPSPI
  TOMPHYSI TONFINSI
  

Fix information

• Fixed component name

  TCP/IP V3 MVS

• Fixed component ID

  5655HAL00

Applicable component levels

• R50A PSY UQ66690

     UP02/06/17 P F206

Fix is available

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