OA19992: AB/S00C4 0004 ISTTSCRO +1332

Obtain the fix for this APAR.

APAR status

• Closed as unreproducible in next release.

Error description

• ABEND0C4 in ISTTSCRO when a session hops from a VR to an
  HPR pipe.
  Aditional symptoms:
  Abend0c4 ISTTSCRO + x'13F6' with failing instruction BAE890E4.
  SYMPTOM STRING:
  RAB/S00C4 LVLS/618 RIDS/ISTAPCFR#R PIDS/5695-11701 ADRS/000013F6
  RIDS/UNKNOWN#L RIDS/ISTTSCRO LVLS/05.231 PTFS/HVT6180 REGS/0B3D9
  PRCS/00000004 ASID/0258
  Additional symptom:
  Abend0c4 ISTTSCRO + x'132E' with failing instruction 95BC9000.
  SYMPTOM STRING:
  RAB/S00C4 LVLS/618 RIDS/ISTAPCFR#R PIDS/5695-11701 ADRS/0000132E
  RIDS/UNKNOWN #L RIDS/ISTTSCRO LVLS/05.231 PTFS/HVT6180 REGS/0B31
  PRCS/00000010 ASID/00E3
  Additional symptoms:
  After an abend in ISTTSCRO a CDRM session may be lost with these
  messages issued.
  IST819I CDRM cdrmname COMMUNICATION LOST - RECOVERY IN PROGRESS
  IST238I AM GUNBIND REQ FOR ID = xxxxxxx RCVD RECOVERY IN
  PROGRESS RU
  DATA TYPE = X'03', CAUSE = X'07'
  Additional symptoms in CICS- various ABENDS reported as:
  DFHSR0601 PROGRAM INTERRUPT OCCURRED WITH SYSTEM TASK TCP IN
            CONTROL
  DFHFC0001 CICSPASP An abend (code 0C1/AKEA) has occurred at
            offset X'547E' in module DFHFCVS
  DFHZC0002 CICSPASP A severe error (code X'FB63') has occurred in
            module DFHZGCC
  DFHAP0001 CICSPASP An abend (code ---/AKEA) has occurred at
            offset X'0230' in module DFHMRXM.
  DFHAP0001 CICSPASP An abend (code 0C4/AKEA) has occurred at
            offset X'044A' in module DFHEISP
  The common factor in all of these dumps was a one byte overlay
  of a what appears to be an OI of x'01'. This was hitting
  CICS code- changing instructions.. one example was
  58F0 F008 was changed to 58F0 F108
  This was occurring in our ERDSA which is Read only- Key 0
  storage.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of RTP connections.                *
  ****************************************************************
  * PROBLEM DESCRIPTION: ABEND0C4 in ISTTSCRO when VR is used    *
  *                      for both sessions from a local          *
  *                      application and sessions arriving       *
  *                      over an HPR pipe.                       *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  The problem is summarized as follows:
  1. A session comes into a VTAM over an HPR pipe and the same
     session goes out of the VTAM over a VR.
  2. Another session originating at an application local to
     that VTAM goes out over the same VR.
  3. While processing the half session queue running in the
     application's address space on the TSOP, ISTTSCRO tries
     to access a BSB associated with the HPR pipe, but the
     BSB is in VTAM private storage, so an ABEND0C4 occurs.
  

Problem conclusion

Temporary fix

Comments

• ISTVRBLK is updated record save the fact that a VR may
  have RTP BSBs on its VRBLK's half session queue if a session
  that traversed an HPR pipe also traverses the VR.
  
  ISTTSCAQ is updated to set the new bit in the VRBLK when
  needed.
  
  ISTTSCRO is updated to not reference the VRBLK's half session
  queue while running in an application's address space if it
  might have an RTP BSB on it.  Instead, it schedules the VRBLK
  PAB to run in VTAM's address space and simulates a flow
  control sequence to force the checking of the half session
  queue while running on the VRBLK PAB.
  

APAR Information

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

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

  UA32669

Modules/Macros

• ISTTSCAQ ISTTSCRO ISTVRBLK
  

Fix information

• Fixed component name

  VTAM V4 MVS/ESA

• Fixed component ID

  569511701

Applicable component levels

• R180 PSY UA32669

     UP07/04/05 P F704

Fix is available

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