There is one potential zIIP performance problem that we learned about as we moved to DB2 V10, which enabled more zIIP processing than was available in V9. The scenario went something like this. zIIP dispatching was not as sophisticated as GP dispatching. If available zIIPs got overloaded, DB2 performance could be severely impacted by a thrashing condition. We actually added another zIIP engine in advance of the V10 cutover.
I have no idea what might have happened otherwise. Was a bullet really dodged or merely imagined? I don't believe that this issue had anything specifically to do with SORT. . . . J.O.Skip Robinson Southern California Edison Company Electric Dragon Team Paddler SHARE MVS Program Co-Manager 323-715-0595 Mobile 626-302-7535 Office [email protected] -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Vernooij, CP (ITOPT1) - KLM Sent: Tuesday, July 19, 2016 7:42 AM To: [email protected] Subject: (External):Re: DFsort and zIIP The largest benefit is a financial one: you don't pay the zIIP MSUs. A performance benefit can come from the fact that the zIIP is always running at full speed, while your CP's can run at lower speeds. Kees. -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Tom Marchant Sent: 19 July, 2016 16:39 To: [email protected] Subject: Re: DFsort and zIIP On Tue, 19 Jul 2016 08:26:45 +0200, Peter Hunkeler wrote: >>DFSORT can use zIIP on behalf of DB2 utilities, but not otherwise. >>Here's more information: > > >>At this time, IBM has no plan for enabling DFSORT to exploit the >>system z9 Integrated Information Processor (zIIP). IBM realizes >>DFSORT remains a prominent component of our customers' batch >>workloads. However, the added controls that would need to be >>implemented in order to maintain our high standards for performance, >>reliability and system integrity are not justified in view of >>estimations that there is a low offload potential and the value to >>clients may be marginal.....[snip] > >I seem to remember that SyncSort offers an Add-On package that allows >certain SyncSort processing to be offloaded to zIIPs. The above >statement suggest that SyncSort's perfocmance is suffering from using >zIIPs (simplified and exagerated, I know). I understood "there is a low offload potential and the value to clients may be marginal" as meaning that there would not be much benefit in using zIIP. Not that it would be worse. -- Tom Marchant ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
