GRSRNLxx (global resource serialization resource name lists)

GRSRNLxx consists of three resource name lists (RNLs). When a global resource serialization complex is active, the system uses these RNLs to determine how to treat the resources defined in the RNLs.

The RNLs are:
  • The SYSTEM inclusion RNL. The system treats each resource named in this RNL as a global resource if an ENQ or a DEQ macro instruction for the resource specifies a scope of SYSTEM.
  • The SYSTEMS exclusion RNL. The system treats each resource named in this RNL as a local resource if an ENQ, DEQ, or RESERVE macro instruction for the resource specifies a scope of SYSTEMS.
  • The RESERVE conversion RNL. The system suppresses a hardware reserve for each resource named in this RNL if a RESERVE macro instruction requests the use of the resource.

GRS requires that the RNLs on every system in the GRS complex be exactly the same in order to maintain a consistent serialization protocol. IBM suggests avoiding the use of system symbols in GRSRNLxx in order to reduce the risk of an RNL mismatch during IPL which would result in a disabled wait state. An RNL mismatch can occur when such a system symbol changes in value, and the symbol resolves to a different value on the system attempting to join the complex than on the systems which are active in the complex.

Note: Specifying RNL=NO on the ENQ macro bypasses all RNL processing. See z/OS MVS Programming: Assembler Services Guide for information about the ENQ macro.

Use the SET GRSRNL command to change the RNL list while the system is active. For more information, see z/OS MVS System Commands.

See z/OS MVS Planning: Global Resource Serialization for detailed information about global resource serialization, RNLs, and the RNL syntax checker. The RNL syntax checker lets you check the syntax of GRSRNL parameters specified on the JCL and resource names specified in GRSRNLxx.