PH07085: SERVICEABILITY ENHANCEMENT FOR A MISSING GROSS LOCK AFTER A LOCKESCALATION

Obtain the fix for this APAR.

APAR status

• Closed as new function.

Error description

• IRLM seviceability enhancement to produce a dump like a case of
  DSNIONX2:504A after a lock escalation to S state where a FETCH
  thread caused a lock escalation to S state, but IRLM did not
  hold Partition L-lock though DM control block indicates Gross
  lock was held .
   Db2 APAR PH07081 - Users can apply IRLM and Db2 APARs in any
  order, but the serviceability will be effective when both are
  applied.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All IRLM2.3 (HIR2230) users od Db2 for z/OS  *
  *                 data sharing SYSPLEXDS.                      *
  ****************************************************************
  * PROBLEM DESCRIPTION: Db2 abend 04E-00C90205 in DSNIONX2 may  *
  *                      occur after a partition lock escalation *
  *                      if RIDs get updated by another member.  *
  ****************************************************************
  * RECOMMENDATION: INSTALL CORRECTIVE SERVICE FOR APAR/PTF      *
  ****************************************************************
  Db2 may issue abend 00C90205 in DSNIONX2 detecting RIDs being
  changed invalidly while it was still holding the gross partition
  level lock after a lock escalation. The dump produced as a
  result of this abend is too late to find information on IRLM
  side how IRLM processed the Change request for the lock being
  escalated. Additional serviceability is required to collect
  more information in the dump to investigate the root cause.
  

Problem conclusion

Temporary fix

Comments

• This APAR adds additional ctraces in IRLM for Db2 lock request
  for lock escalation when Db2 APAR PH07081 is also applied.
  Db2 would flag lock escalation requests in PH07081, which would
  enable IRLM to write a ctrace entry in its DIA trace buffer.
  This additional documentation when captured in Db2 04E-00C90205
  dump, should help in diagnosing this locking issue. The impact
  of additional ctrace should be very minimal.
  

APAR Information

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

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

  UI61405

Modules/Macros

•    DXRRL109 DXRRL120 DXRRL150 DXRRL2T0 DXRRL770
  

Fix information

• Fixed component name

  IRLM V2

• Fixed component ID

  569516401

Applicable component levels

• R230 PSY UI61405

     UP19/03/09 P F903

Fix is available

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