Coupling Thin Interrupts on zBC12 and zEC12 servers
KieronHinds 100000J76H Visits (7233)
IBM introduced support for Coupling Thin Interrupts with CF Level 19 on zBC12 and zEC12 servers. Coupling thin interrupts are designed to improve the efficiency of environments where shared engines are used by Coupling Facilities. It does this by allowing a coupling facility to voluntarily give up control of the shared coupling facility processor whenever it runs out of work to do, and later expediting the re-dispatching of the partition to allow it to resume polling logic that is optimal for CFCC to locate and process work. In most shared processor configurations, coupling facilities should achieve a performance benefit when Coupling Thin Interrupts are enabled. The amount of benefit is discussed in whitepaper
As a result, we strongly recommend using coupling thin interrupts in all coupling facilities that share processors running on zEC12 and zBC12 servers.
Additionally, Coupling thin interrupts may make it possible to share a pool of coupling facility engines with reasonably good performance where it was not possible to do so previously. This may help you achieve more flexible coupling facilities configuration options without having to purchase more coupling facility engines.
IBM still recommends that dedicated coupling facility processors be used in environments where significant use of CF resources is required and where the absolute best performance is required.
Still, with coupling thin interrupts, we feel coupling facilities with shared processors are now a much more viable configuration option, and we intend to share some practical examples in upcoming updates. In the meantime, we would love to hear your thoughts on using shared engines and coupling thin interrupts.