Just to close the loop on this - we found an obscure latent bug deep inside one of our components which resulted in the request for excessive memory when very specific types of data were encountered.
Most users probably wouldn't have had that kind of data, and even those who did might not have noticed the problem - since unless their REGION was capped at a lowish value, the external symptom is just that the job takes longer to execute - it still performs the requested operations. Thanks again to everyone for all the ideas / advice, which was quite helpful in chasing this down! Rich Way -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Ron Hawkins Sent: Tuesday, August 01, 2017 12:06 PM To: [email protected] Subject: Re: REGION=0M leads to CPU through the roof Agree. Even RMF II is going to tell you more than you can see from step end messages. -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Rob Schramm Sent: Friday, July 28, 2017 2:51 AM To: [email protected] Subject: Re: [IBM-MAIN] REGION=0M leads to CPU through the roof Turn on a monitor while the step is running? With 12 min of CPU, there is time to dig into it. Rob On Fri, Jul 28, 2017, 4:10 AM Ron Hawkins <[email protected]> wrote: > Gerhard, > > Now what if the searching you describe was a sequential scan of said > table, and the LPAR had only 1GB of storage defined? > > Ron > > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:[email protected]] > On Behalf Of Gerhard Adam > Sent: Thursday, July 27, 2017 8:19 PM > To: [email protected] > Subject: Re: [IBM-MAIN] REGION=0M leads to CPU through the roof > > I don't see paging as the culprit. To page out 1.6 GB of memory and > then reference it to bring it back in still indicates an application problem. > Especially with a total elapsed time of only 12 minutes. > > I suspect that the application built a table. Spent wasted time > searching it. > > Sent from my iPhone > > > On Jul 27, 2017, at 6:50 PM, Ron Hawkins <[email protected]> > wrote: > > > > Charles, > > > > YES I AGREE, storage nowadays can do a lot of paging, and support a > > CEC easily burning 11 minutes of CPU time paging. DPR rates of > > 100,000/sec are a walk in the park for current IBM, EMC or HDs > > controllers, and probably higher on a boxes that can do >2,000,000 > > cache > hits a second. > > > > Of course, if the OP is not actually going to look at anything but > > the CPU time, he will probably never find out what cause it. > > > > Ron > > > > -----Original Message----- > > From: IBM Mainframe Discussion List > > [mailto:[email protected]] On Behalf Of Charles Mills > > Sent: Wednesday, July 26, 2017 5:37 PM > > To: [email protected] > > Subject: Re: [IBM-MAIN] REGION=0M leads to CPU through the roof > > > > By ELEVEN CPU MINUTES??? > > > > A modern processor can do a heck of a lot of paging with 11 CPU minutes. > > > > Charles > > > > > > -----Original Message----- > > From: IBM Mainframe Discussion List > > [mailto:[email protected]] On Behalf Of Ron Hawkins > > Sent: Wednesday, July 26, 2017 5:08 PM > > To: [email protected] > > Subject: Re: REGION=0M leads to CPU through the roof > > > > Richard, > > > > You used 1.6GB of virtual storage. > > > > How much paging did the address do? There's no free lunch, and page > > faults will increase the TCB time for an address. > > > > -------------------------------------------------------------------- > > -- For IBM-MAIN subscribe / signoff / archive access instructions, > > send email to [email protected] with the message: INFO > > IBM-MAIN > > > > -------------------------------------------------------------------- > > -- For IBM-MAIN subscribe / signoff / archive access instructions, > > send email to [email protected] with the message: INFO > > IBM-MAIN > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, send > email to [email protected] with the message: INFO IBM-MAIN > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, send > email to [email protected] with the message: INFO IBM-MAIN > -- Rob Schramm ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
