PM20701: POLICY AGENT LOCK CONTENTION COULD LEAD TO STORAGE GROWTH OR ABEND

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Policy Agent may hold on to a lock when a thread is terminating
  which can prevent new threads from obtaining this lock, leading
  to thread growth which can be seen as a private storage growth
  or attach failure.
  
  Verification Steps:
  
  IP ANALYZE RESOURCE will show
  
  RESOURCE #0023:
  
     NAME=Mutex Object ADDR=1DE4EF38
  
  RESOURCE #0023 IS HELD BY:
  
    JOBNAME=PAGENT    ASID=004A  TCB=009CA960
     DATA=MSB ADDR: 1DD73540 SQEL ADDR: 1E64ED78 CAA ADDR:
  1E64FBD8 USER MUTEX/CV
  
  RESOURCE #0023 IS REQUIRED BY:
  
    JOBNAME=PAGENT    ASID=004A  TCB=009BC8B0
     DATA=MSB ADDR: 1DD73540 SQEL ADDR: 209C8D78 CAA ADDR:
  209C9BD8
  
  IP VERBX LEDATA 'NTHREADS ASID(xx)' , where xx is Policy
  Agents ASID, will show many TCBs with tracebacks like:
  
  Traceback:
    DSA      Entry       E  Offset
  
    1        CEEOPML2    -02361D50
    2        plfm_thread_mutex_lock
                         +0000006C
    3        pdp_thread_mutex_lock
                         +000002A4
    4        pmonapps_image_active
                         +00000082
    5        check_config_files
                         +00000AB6
    6        CEEPGTFN    +0000005A
    7        CEEOPCMM    +00000982
  
  
  
  
  Keywords: ABEND92A RC18 PAGENT
  

Local fix

• Recycling Policy Agent will clear this situation.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of the IBM Communications Server   *
  *                 for z/OS Version 1 Release(s) 11, and        *
  *                 12 IP: Policy Agent                          *
  ****************************************************************
  * PROBLEM DESCRIPTION: Cancelation processing on a thread      *
  *                      can lead to lock contention for the     *
  *                      pmonMutex lock in Policy Agent.         *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  Policy Agent may hold on to a lock when a thread is terminating
  which can prevent new threads from obtaining this lock. The
  Policy Agent's log would have the following traces:
  
  08/15 17:56:58 LOG    :005: check_config_files: pmonMutex
  (1DE4EF38) locking
  08/15 17:56:58 SYSERR :005: check_config_files:
  plfm_thread_mutex_lock() Mutex lock failed, errno EDC5116I
  Resource deadlock avoided.
  
  A similar problem can occur with Policy Agent's handling of
  the AffinityMutex.
  +-------------------------------------------------------------+
  + 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 Policy Agent code has been modified to handle the lock
  contention for the pmonMutex and the AffinityMutex.
  
  * Cross Reference between External and Internal Names
  EZAPAPPR (PPROFILE)  EZAPAPPR (PPROFILE)
  

Temporary fix

Comments

APAR Information

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

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

  UK60294 UK60295

Modules/Macros

• EZAPAPPR EZAPAPPS
  

Fix information

• Fixed component name

  TCP/IP V3 MVS

• Fixed component ID

  5655HAL00

Applicable component levels

• R1B0 PSY UK60294

     UP10/10/27 P F010

• R1C0 PSY UK60295

     UP10/10/27 P F010

Fix is available

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