OA42764: HUNG CP-CP SESSIONS AFTER AN ABEND0C4 OCCURS IN ISTLUCRP

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Hung CP-CP sessions after an ABEND0C4 occurs.  Locates hang
  and CP-CP sessions are unable to be established.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of VTAM APPC (APPC=YES on the      *
  *                 VTAM APPL statement) and/or VTAM APPN        *
  ****************************************************************
  * PROBLEM DESCRIPTION: CP-CP processes hung after ABEND        *
  *                      in ISTLUCRP                             *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  The problem may be summarized as follows:
  1. CP-CP session initialization is started.
  2. While the Init_Other for the session is
     outstanding, an APPCB control block (NSSCB)
     is prematurely freed. (APAR OA42811 has been
     taken to address this issue.)
  3. When the Init_Other response returns, LUS references
     the freed control block.  ISTLUCSL ABENDs and then
     ISTLUCRP ABENDs.
  4. The ISTLUCRP ABEND is executing on the APPCB PAB and
     is not covered by a VTAM Recovery Routine (VRR),
     so the PAB is left undispatchable.
  5. As a result, CP-CP sessions hang and so do Locates.
     After this error occurs, no new CP-CP sessions may be
     established and no existing CP-CP sessions may be
     taken down. A D NET,CPCP display will show CP-CP
     sessions in various pending states.
  6. This APAR addresses the lack of recovery (VRR), rather
     than the issue leading up to the reported ABENDs.  The
     new recovery added by this APAR will allow VTAM to continue
     processing new CP-CP requests after these ABENDs.
  

Problem conclusion

• ISTPSCR1 is updated to provide VRR coverage around
  the call to ISTOCCSM/ISTLUCRP.
  
  ISTNSCLR is 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:

  UA69880 UA69881 OA42982

Modules/Macros

• ISTNSCLR ISTPSCR1
  

Fix information

• Fixed component name

  VTAM V4 MVS/ESA

• Fixed component ID

  569511701

Applicable component levels

• R1C0 PSY UA69880

     UP13/07/23 P F307 Ž

• R1D0 PSY UA69881

     UP13/07/23 P F307 Ž

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.