How global resource serialization determines the scope of an ENQ or RESERVE request

Global resource serialization might change the scope of an ISGENQ, ENQ or RESERVE request that was issued with a SCOPE of SYSTEM or SYSTEMS (unless the request specified RNL=NO).

If an ENQ is issued with a scope of SYSTEM, and matches an entry in the SYSTEM inclusion RNL but does not match an entry in the SYSTEMS exclusion RNL, then global resource serialization changes the scope of the request from SYSTEM to SYSTEMS (and processes the resource as a global resource). A GQSCAN with SCOPE=SYSTEM or SCOPE=LOCAL will not find a match on such a request.

If an ENQ or RESERVE is issued with a scope of SYSTEMS, and either it matches an entry in the SYSTEMS exclusion RNL, or the system is running with GRSRNL=EXCLUDE, then GRS changes the scope of the request from SYSTEMS to SYSTEM (and processes the resource as a local resource). A GQSCAN with SCOPE=SYSTEMS or SCOPE=GLOBAL will not find a match on such a request.

When issuing a GQSCAN for a resource whose scope might have been changed, you might find it desirable to specify SCOPE=ALL in order to match requests whether or not they have been changed.