CQS-managed rebuild

CQS-managed rebuild is a process by which CQS manages structure rebuild. CQS supports two variations of CQS-managed rebuild: structure copy and structure recovery.

Structure copy copies the contents of the structure to another structure, for a planned reconfiguration or connectivity loss. Structure copy can also be used to activate new CFRM policy attributes. Structure recovery recovers a structure from the SRDS and the z/OS® log after a structure failure.

If one CQS loses connectivity to a structure and another CQS still has connectivity to that structure, CQS manages the structure rebuild and performs a structure copy. If all CQSs lose connectivity to a resource structure, structure recovery is attempted, but fails because structure recovery is not supported for resource structures or for nonrecoverable queue structures (RECOVERABLE=NO).

If a coupling facility or queue structure fails, CQS performs a structure recovery.

If a resource structure fails, it is lost and structure rebuild is not performed. CQS is not able to perform structure recovery because resource structures do not support checkpoint and logging. CQS clients can repopulate the failed resource structure. CQS attempts to allocate a new resource structure.

If a new structure is successfully allocated, CQS drives the client structure event exit with the repopulate structure event. The CQS client or clients must then repopulate the structure. If a new structure is not successfully allocated, CQS drives the structure exit event with the structure failed event. The structure is not accessible for repopulation. Correct the environmental problem that caused the structure allocate to fail so that the structure can be allocated and repopulated.