OA66826: ZDMF LOGICAL COPY GROUP HANGS AND IS UNRESPONSIVE

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• zDMF logical copy group hangs and is unresponsive.a D GRS,C
  command shows contention on SYSIGGV2 resource and SYSZTIOT.  A
  zDMF task holds a SYSIGGV2 resource and is waiting on the
  SYSZTIOT resource. Another zDMF task holds the SYSZTIOT resource
  and by proxy via CATALOG is waiting on the SYSIGGV2 resource.
  
  A classic ENQ deadlock condition.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: zDMF 3.4.1 using Logical Copy and activating *
  *                 multiple groups concurrently.                *
  ****************************************************************
  * PROBLEM DESCRIPTION: zDMF logical copy group hangs and is    *
  *                      unresponsive. A D GRS,C command shows   *
  *                      contention on SYSIGGV2 resource and     *
  *                      SYSZTIOT.  A zDMF task holds a SYSIGGV2 *
  *                      resource and is waiting on the SYSZTIOT *
  *                      resource. Another zDMF task holds the   *
  *                      SYSZTIOT resource and by proxy via      *
  *                      CATALOG is waiting on the SYSIGGV2      *
  *                      resource.                               *
  *                                                              *
  *                      A classic ENQ deadlock condition.       *
  ****************************************************************
  While one group is in ACTIVATION phase which entails allocating
  source and target data sets and performing data set copy,
  another group is in DIVERT phase which entails renaming source
  and target data sets. The diverting task incurs an error
  renaming a source and target data set and enters a backout
  process to reverse whatever has been done. During the backout,
  the target catalog is DEQueued followed by the release of the
  SYSZTIOT resource. The group in ACTIVATION has been serialized
  by the SYSZTIOT resource during allocation activities for source
  and target data sets. With the release of SYSZTIOT the
  ACTIVATION allocation process of a source data set proceeds with
  a CATALOG request that begins with an ENQueue of the SYSIGGV2
  resource for the source data set catalog. In the meantime the
  DIVERT taak proceeds to close the target data set catalog.
  However, the CLOSE routine requires the SYSZTIOT resource which
  is still held by the ACTIVATION task which is delayed waiting on
  the aforementioned  SYSIGGV2 resource (still held by the DIVERT
  task). Hence a deadlock occurs between these two tasks.
  

Problem conclusion

• GZDRMAN is changed preserve the order that the SYSZTIOT resource
  is obtained with respect all the catalog resources acquired
  during the DIVERT process.
  

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:

  UJ96338

Modules/Macros

• GZDRMAN
  

Fix information

• Fixed component name

  ZDMF

• Fixed component ID

  ZDMF00001

Applicable component levels

• R341 PSY UJ96338

     UP24/11/21 P F411

Fix is available

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