Performance enhancements for lock structures with record data

z/OS® V1R4 and APAR OW52437 provide performance improvements for lock structures with record data in a system-managed CF structure duplexing environment. Compatibility for the improvements is available for systems in the sysplex at OS/390® V2R8 and higher through APAR OW52266.

The performance improvements may increase the size of an existing lock structure; perhaps an additional 300K of space in the coupling facility may be required. Currently allocated lock structures with record data must be reallocated through the rebuild process to acquire the additional storage in preparation for system-managed CF structure duplexing.

The following procedure outlines the steps to provide compatibility for the performance improvements.

Apply OW52266 on all systems in the sysplex.
Use the CF Structure Sizer (CFSizer) tool to determine the appropriate size for all lock structures except ISGLOCK. (The ISGLOCK structure cannot exploit the new performance enhancements because the structure does not contain record data.)
The CF Structure Sizer (CFSizer) tool is found at http://www.ibm.com/systems/support/z/cfsizer/
Update the CFRM policy to specify the new lock structure size requirements.

The following procedure outlines the steps to enable the lock structure performance improvements provided in OW52437.

Apply OW52437 to systems in the sysplex only after OW52266 is installed and active on all systems in the sysplex.
Initiate® a rebuild to activate the performance enhancements with multiple record data lists.
When the rebuild completes, issue the DISPLAY XCF,STR command with at least one structure name to verify that the structure has been allocated with multiple record data lists and is ready for system-managed CF structure duplexing. If so, message IXC360I will contain the insert ‘NUMBER OF RECORD DATA LISTS PER CONNECTION: nnn’.
If the message insert does not appear, the structure was allocated by a system that does not have the support provided by OW52437.

For more information, see System-Managed Coupling Facility Structure Duplexing at the following URL:

http://public.dhe.ibm.com/common/ssi/ecm/en/zsw01975usen/ZSW01975USEN.PDF