IBM SC34-7012-01 manual Coupling facility data table retained locks

Coupling facility data table retained locks

Recoverable coupling facility data table records can be the subject of retained locks, like any other recoverable CICS resource that is updated in a unit of work that subsequently fails.

A recoverable CFDT supports indoubt and backout failures. If a unit of work fails when backing out an update to a CFDT, or if it fails indoubt during syncpoint processing, the locks are converted to retained locks and the unit of work is shunted. If a CFDT record is locked by a retained lock, an attempt to modify the record fails with the LOCKED condition. This can be returned on the following API file control requests issued against CFDT records:

vDELETE with RIDFLD

vREAD with UPDATE

vREADNEXT with UPDATE

vREADPREV with UPDATE

vWRITE

To resolve retained locks against CFDT records, use the CEMT INQUIRE UOWLINK command to find the unresolved units of work associated with links to the coupling facility data table pool containing the table. When you have found the UOW links, take the appropriate action to resolve the link failure or force completion of the UOWs.

The owner of the failed UOW could be another CICS region in the sysplex, and the cause of the retained lock could be one of the following:

vThe CICS region cannot resolve the UOW because its CFDT server has failed.

vThe CICS region that owns the UOW has failed to connect to its CFDT server.

vThe CICS region that owns the UOW cannot resynchronize with its CFDT server.

vAn indoubt failure caused by the loss of the CICS region that is coordinating a distributed UOW.

vAn indoubt failure caused by the loss of connectivity to the CICS region that is coordinating a distributed UOW.

182CICS TS for z/OS 4.1: Recovery and Restart Guide