PH67143: IMS RESTART CAN HANG AFTER OPERATING IZTRAN WHEN THE ETOS OPTIONS DATASET IS ACCESSED AS VSAM AND SHARED AMONG MULTIPLE IMSS

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• When the following conditions are all met, IMS restart hangs
  after issuing "IZT4107I DBIZT1 DSN=data_set_name" or "IZT4108I
  E/CSA DATA BASE SECTION ADDRESS: address" messages,
  *** ETOS Options dataset is configured to be accessed as VSAM
  (not IMS DB).
  *** ETOS Options dataset is shared among multiple IMSs.
  *** IZTRAN, ETOS provided IMS MPP to offer a panel UI, is
  terminated by pressing PF3 key or sending "END" command in the
  "IZTRAN PRIMARY MENU" panel.
  ** This problem is caused by resource contention. The situation
  can be restored by the following procedure,
  ### Rerunning the IZTRAN transaction (the contention is released
  by this step).
  ### Terminate the IMS session without pressing the PF3 key on
  the "IZTRAN PRIMARY MENU" panel (e.g., wait until auto-signoff
  time, clear the screen and then sign off).
  

Local fix

• N/A
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All IBM IMS Extended Terminal Option Support *
  *                 for z/OS Version 3 Release 2 (FMID=H1J4320)  *
  *                 users.                                       *
  ****************************************************************
  * PROBLEM DESCRIPTION: IZTRAN, which is ETOS provided IMS MPP  *
  *                      that provides UI for ETOS               *
  *                      configuration, kept the ETOS options    *
  *                      dataset exclusively enqueued after a    *
  *                      specific operation. It caused a hang    *
  *                      when the other IMS restarted; the IMS   *
  *                      initialization process was waiting for  *
  *                      the dequeue of the ETOS options         *
  *                      dataset.                                *
  *                                                              *
  *                      It occurred when the following          *
  *                      conditions were all met,                *
  *                      1. the ETOS options dataset was         *
  *                         configured as VSAM (not IMS DB)      *
  *                      2. the ETOS options dataset was shared  *
  *                         among multiple IMSs.                 *
  *                      3. the MPP region running IZTRAN was    *
  *                         configured PWFI=Y (Pseudo            *
  *                         Wait-for-Input was enabled)          *
  ****************************************************************
  * RECOMMENDATION: Apply the maintenance for this APAR.         *
  ****************************************************************
  When the ETOS options dataset is configured as VSAM (not IMS
  DB), the IZTRAN transaction process enqueues the ETOS options
  dataset at entry of the process, and then dequeues it at exit.
  However, when the MPP region was PWFI=Y, and the PF3 key or
  "END" command was entered on the "IZTRAN PRIMARY MENU" panel,
  the IZTRAN entered a wait state for the next message without
  dequeuing the ETOS options dataset.
  
  On the other hand, the ETOS initialization process, which runs
  during the IMS initialization process, enqueues the ETOS options
  dataset in preparation for an internal error of the ETOS options
  dataset.
  
  Therefore, when the options dataset was shared among multiple
  IMSs, the IMS initialization process hung after issuing IZT4107I
  or IZT4108I messages due to the ETOS initialization process
  waiting for the dequeue of the ETOS options dataset.
  
  For example, when IMS1 and IMS2 shared the ETOS options dataset,
  the initialization process of IMS2 can hang due to IZTRAN
  running in IMS1.
  

Problem conclusion

• The internal process of IZTRAN has been fixed. It now dequeues
  the ETOS options dataset even when the PF3 key or "END" command
  is entered on the "IZTRAN PRIMARY MENU" panel.
  

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:

  UO04522

Modules/Macros

• IZTRAN
  

Fix information

• Fixed component name

  IMS ETO SUPPORT

• Fixed component ID

  5655E1200

Applicable component levels

• R320 PSY UO04522

     UP25/08/23 P F508

Fix is available

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