The HISSERV service can be used by authorized products to retrieve hardware instrumentation event and sampling data directly from storage.
Although individual products can query the service for any subset of event types they desire, the sampling parameters are global to every product that intends to collect sampling data. The global sampling parameters, or service parameters are set by the most recent MODIFY HIS,BEGIN or MODIFY HIS,SERVICE command. A profiler chooses how often to collect event type data and how much time is spent processing sampling data, but the frequency is global for all profiler's collecting sampling data. Any of these might cause a performance degradation to the system and should be carefully decided.
For details, see the HISSERV service interface in z/OS MVS Programming: Authorized Assembler Services Reference EDT-IXG, and for information on the MODIFY HIS,BEGIN or MODIFY HIS,SERVICE commands, see Starting, configuring, and stopping hardware event data collection.
