PH17496: Task stuck in IS_PACE wait and IPCONN is stuck in freeing state

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Task is stuck in an IS_PACE wait loop.
  This waits for a pacing response message to arrive.
  If the wait times out but the ISSS error flags are off
  then the task waits again.
  In this case both ISSS_SESS_ERROR and ISSS_CONN_ERROR
  are off even though the IPCONN was being released due
  to a socket error.
  CICS IPCONN status is FREEING and tasks were in SUSPENDED
  state with resource IS_PACE.
  The error flags ISSS_SESS_ERROR and ISSS_CONN_ERROR should
  not be off when the task is suspended in an IS_PACE wait, it
  causes IS_PACE wait problem.
  
  This APAR will also resolve DFHIS0002 SEVERE ERROR X'180C' IN
  MODULE DFHISRE caused by the underlying socket connection being
  closed while the CISS task is in resync processing.  The trace
  for this case will show
    IS 0712 ISSR  *EXC* INVALID_STATE         RECEIVE_REQUEST
    IS 0701 ISSR  EXIT  RECEIVE_REQUEST/EXCEPTION INVALID_STATE
    IS 0901 ISZA  EXIT  RECEIVE_REQUEST/DISASTER
    IS 180C ISRE  *EXC* RECEIVE_ERROR         CICS_RESYNC,...
  
  CICS TS 5.3 is fixed by PH25903.
  
  Additional Symptom(s) Search Keyword(s):
  KIXREVDAM
  

Local fix

• No Workaround
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICS users.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: Mirror task is stuck in an IS_PACE wait *
  *                      loop which causes IPCONN to remain in   *
  *                      FREEING state.                          *
  ****************************************************************
  A request arrives through IPIC connection and a mirror task is
  attached to run. It is in the middle of sending large size of
  response data and waits 10 seconds for PACE message. At this
  point, a connection error happened on the session which is used
  for receiving PACE message. This session is added to the error
  queue with flags (isss_error_code, isss_sess_error and
  isss_conn_error) setting to record the session error. CISE is
  resumed to handle the error queue. It attaches CIST and then
  clears the session error flags. CIST begins terminating the
  IPCONN but waits for the mirror task to complete. When mirror
  task wait times out it can not detect the connection error
  because the error flags has been cleared, and waits for another
  10 seconds which repeats forever. This causes the IPCONN to stay
  in FREEING status and it can not be released.
  

Problem conclusion

• DFHISEM has been changed to only clear the error flags if the
  session is in released status, which makes sure the mirror task
  can be terminated and IPCONN can be released.
  

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:

  UI67971 UI67972

Modules/Macros

• DFHISEM
  

Fix information

• Fixed component name

  CICS TS Z/OS V5

• Fixed component ID

  5655Y0400

Applicable component levels

• R100 PSY UI67971

     UP20/02/20 P F002

• R200 PSY UI67972

     UP20/02/20 P F002

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.