IBM SC34-7012-01 Resolving retained locks and preserving data integrity, Shcds List subcommands

vCommit failure, where a unit of work has failed during the commit action. The commit action may be either to commit the changes made by a completed unit of work, or to commit the successful backout of a unit of work. This failure is caused by a failure of the SMSVSAM server, which is returned as RLSSERVER on the CAUSE option and COMMITFAIL or RRCOMMITFAIL on the REASON option of the INQUIRE UOWDSNFAIL command. (RLSSERVER is also returned as the WAITCAUSE on an INQUIRE UOW command.)

Commit failures can be retried after the cause of the failure has been corrected. The retry usually occurs automatically.

Note that INQUIRE UOWDSNFAIL displays information about UOWs that are currently failed with respect to one or more data sets. The command does not display information for a unit of work that was in backout-failed or commit-failed state and is being retried, or for a unit of work that was indoubt and is being completed. The retry, or the completion of the indoubt unit of work, could fail, in which case a subsequent INQUIRE UOWDSNFAIL displays the relevant information.

SHCDS LIST subcommands

A CICS region that has been accessing a data set may not be running at the time you want to inquire on unit of work failures in readiness for a batch job.

Instead of bringing up such a CICS region just to issue INQUIRE UOWDSNFAIL commands, you can use the SHCDS LISTDS, LISTSUBSYS, or LISTSUBSYSDS commands. These commands enable you to find out which CICS regions (if any) hold retained locks, and to obtain other information about the status of your data sets with regard to each CICS region. You then know which regions you need to start in order to resolve the locks. These commands are described in z/OS DFSMS: Access Method Services for ICF.

The SHCDS LIST commands could also be useful in the unlikely event of a mismatch between the information that CICS holds about uncommitted changes, and the information that the VSAM RLS share control data set holds about retained locks.

Resolving retained locks and preserving data integrity

Unless prevented by time constraints, you are recommended to resolve retained locks by using the INQUIRE UOWDSNFAIL command and retrying shunted UOWs.

About this task

Procedure

1.Use the INQUIRE UOWDSNFAIL command to find out which failed component has caused the UOW to have retained locks for this data set.

2.If a unit of work that has been shunted with a CAUSE of DATASET and a REASON of DELEXITERROR, enable a suitable global user exit program at the XFCLDEL (logical delete) global user exit point and then issue a SET DSNAME ACTION(RETRY) command to retry the backout and drive the global user exit.

3.If a unit of work that has been shunted with a CAUSE of CONNECTION, use the SYSID and NETNAME returned by INQUIRE UOWDSNFAIL to find out what has caused the indoubt condition and correct the failure, after which automatic resynchronization should allow the unit of work to complete, either by being backed out or by committing the changes.

176CICS TS for z/OS 4.1: Recovery and Restart Guide