PQ52900: CSM ECSA STORAGE AT CRITICAL LEVEL, STORAGE ALLOCATION FAILED IN CSM STORAGE, SENDTO ERROR NO BUFFER SPACE AVAILABLE.

Obtain the fix for this APAR.

APAR status

• Closed as unreproducible in next release.

Error description

• This failure can only occur when CSM is constrained.
  In the CSM storage there are many 32K buffer allocated.
  IP VERBX VTAMMAP 'CSMPOOL CSMSIZE(32K) CSMTYPE(ECSA)'
  BUFFER BUFFER
  SIZE   SOURCE             STORAGE ALLOCATED TO OWNER
    32K  ECSA                          71424K
  The storage has IUDIs and IUDRs in it.  The IUDIs show as
  still in use.
  VERIFICATION STEPS:
   Look at the csm 32K csmsize storage with many IUDRs and one
   or more IUDIs.  The IUDIs are still showing in use and the
   IUDRs are not in use.
  KEYWORDS:  storage shortage iudr iudi constrained
  

Local fix

• Correct what is causing the CSM storage constraint
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of the IBM Communications Server   *
  *                 for OS/390 Release 10 IP                     *
  ****************************************************************
  * PROBLEM DESCRIPTION: CSM ECSA fills with IUDI control blocks *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  During a SYN attack, a surge in storage allocation caused
  CSM ECSA to become constrained. When EZBIFINB failed to obtain
  an MDATA, it exited without freeing the MPROTO which further
  compounded the storage problem.
  +-------------------------------------------------------------+
  + 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

• Module EZBIFINB has been changed to properly free the
  storage.
  This APAR contains the fixes for PTRs MV23314 and MV22672.
  

APAR Information

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

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

  UQ58916

Modules/Macros

• EZBIFINB
  

Fix information

• Fixed component name

  TCP/IP V3 MVS

• Fixed component ID

  5655HAL00

Applicable component levels

• R50A PSY UQ58916

     UP01/11/06 P F111

Fix is available

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