OW52758: STORAGE GROWTH IN SP231 KEY 6

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Storage growth of Subpool 231 Key 6 with 4k blocks,
  because storage is not freed. 3FF00000
  Below is a sample from a dump of
  what the storage in SP231 can look like:
  ----------------------------------------
  1FD74000   2072C6D0   205A92C0 ' E7406000   00004000
  1FD74010.:1FD740BF.--All bytes contain X'00'
  1FD740C0   00000000   00000000   00000000   3FF00000
  1FD740D0.:1FD77FFF.--All bytes contain X'00'
  1FD78000   207360B0   206D32C0   E7406000   00004000
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All using APPN Host-Host Channel (AHHC) or   *
  *                 the following types of configurable TCP/IP   *
  *                 connections:                                 *
  *                                                              *
  *                 ATM, CDLC, CLAW, CTC, HCH (Hyperchannel),    *
  *                 LCS, MPCIPA (QDIO), MPCOSA,                  *
  *                 MPCPTP (XCF or Enterprise Extender),         *
  *                 SAMEHOST (SNALINK,SNALU62, or X25NPSI)       *
  ****************************************************************
  * PROBLEM DESCRIPTION: CSA Storage shortage due to NCBs not    *
  *                      being freed after a device activation   *
  *                      failure.  This may lead to CMS FFST     *
  *                      probe IVTSMC05 and the following error  *
  *                      message:                                *
  *                                                              *
  *                        IVT5506I IVTSMCEX STORAGE ALLOCATION  *
  *                                 FAILED IN CSM                *
  *                                                              *
  *                      A device activation failure message     *
  *                      similar to the following may also be    *
  *                      reported:                               *
  *                                                              *
  *                        EZZ4310I ERROR: CODE=80100044         *
  *                                 REPORTED ON DEVICE xxxxxxxx. *
  *                                 DIAGNOSTIC CODE: 03          *
  *                                                              *
  *                      SP 231 is full of MPNCBs or TLNCBs      *
  *                      containing non-zero NCB_Age_Retry       *
  *                      values.  For most NCBs, the value is    *
  *                      equal to NCB_Age_Retry_Lim (7).         *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  A TCP/IP device is activated, causing the appropriate NCB to be
  created.   For TCP Legacy devices, a TLNCB is created on the
  RMCUTPAB (IUTLLCRU) upon schedule from the RMCRMPAB (IUTLLCRM).
  For MPC-type devices, an MPNCB is created directly on the
  RMCRMPAB.  Following NCB creation, IUTLLCRM constructs an RM
  connection object to represent the device.
  
  Device activation later fails at some unknown point. As part of
  the cleanup, the RM connection object is invalidated via the
  Conn_Invalidate or Reg_Mgr Invalidate_Token method (this can
  occur in many places depending on where exactly the activation
  failed). This begins the aging time for the object (16 seconds).
  
  The aging timer expires allowing the aging module IUTLLCRA to
  process the object.  In this particular failure scenario,
  however, the NCB_Age_Ready bit within the NCB is never turned
  on during cleanup, so aging of the object keeps getting delayed
  to the next aging cycle until the maximum aging retry limit
  (NCB_Age_Retry_Lim) is hit.  At that point, the NCB storage is
  forfeited.
  
  Enough failed device activations over time will eventually
  cause the CSA storage shortage that is being experienced.
  

Problem conclusion

• There are 2 types of device activation failures where the bit
  NCB_Age_Ready is never turned on:
  
    1) Those that fail before a DIUTIL ACTPATH REQ is sent.
    2) Those for which the ACTPATH REQ results in a negative
       response.
  
  In each case, the failure is too early for deactivation flows
  (i.e., DIUTIL DACTPATH REQ) to be invoked to clean up the
  resource.  Such failures are handled by via special activation
  failure logic.  Type 1) failures are handled by IUTLLCRM in
  segment ACTPATH.  Type 2) failures are handled by IUTLLCRD
  negative ACTPATH RSP processing.
  
  To ensure NCB_Age_Ready is turned on in case 1), IUTLLCRM
  segment ACTPATH has been changed to set the bit upon exit if
  the RMLCB FSM is reset.  This will only be the case if
  activation failed and no DIUTIL DACTPATH REQ was issued.
  An exception to this rule is the handling of ACTPATH REQ
  failures for the TCP Legacy DLCs, which are offloaded to the
  RM Utility PAB (IUTLLCRU) so IUTLLCTC can clean up the TRLE.
  That module will set NCB_Age_Ready once the NCB and RMLCB
  no longer needed.
  
  To ensure NCB_Age_Ready is turned on in case 2), ISTLLCM8,
  ISTTSCM8, ISTTSC8X, ISTTCCQV, and ISTTCCRI will set the bit when
  issuing negative ACTPATH responses.
  
  It was also discovered that NCB_Age_Ready needs to be turned on
  as DIUTIL DACTPATH RSP is issued from ISTTSC8X and ISTTCCQV.
  
  With this fix, all DIUTIL ACTPATH REQ, ACTPATH RSP, and
  DACTPATH RSP invokers within VTAM now set NCB_Age_Ready as
  needed. The single exception is ISTLLCD8 because it deals with
  DINCBs, which are not subject to aging.
  
  ISTTCCTE and IUTLLCRA have been included for maintenance
  purposes only.
  

Temporary fix

• *********
  * HIPER *
  *********
  

Comments

APAR Information

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

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

  UW86312 UW86313 UW86314 UW86315

Modules/Macros

• ISTLLCM8 ISTTCCQV ISTTCCRI ISTTCCTE ISTTSCM8
  ISTTSC8X IUTLLCRA IUTLLCRM IUTLLCTC
  

Fix information

• Fixed component name

  VTAM V4 MVS/ESA

• Fixed component ID

  569511701

Applicable component levels

• R10A PSY UW86314

     UP02/02/26 P F202 Ž

• R120 PSY UW86315

     UP02/02/26 P F202 Ž

• R701 PSY UW86312

     UP02/02/26 P F202 Ž

• R801 PSY UW86313

     UP02/02/26 P F202 Ž

Fix is available

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