I'm hoping my colleague Dave Betten will chime in on this at some point. Particularly as z/OS 2.1 DFSORT has some enhancements in this area.
CONCURRENCY is always the challenge here. And equally I would reinforce MEMLIMIT with a decent IEFUSI exit (which I would hope included limiting hiperspace). I've seen this scenario a number of times, often represented by the RMF interval-level Minimum Available Frames being near zero while the interval-level Average Available Frames is usually (but not always) somewhat higher. Cheers, Martin Martin Packer, zChampion, Principal Systems Investigator, Worldwide Banking Center of Excellence, IBM +44-7802-245-584 email: [email protected] Twitter / Facebook IDs: MartinPacker Blog: https://www.ibm.com/developerworks/mydeveloperworks/blogs/MartinPacker From: "R.S." <[email protected]> To: [email protected] Date: 05/08/2014 11:28 Subject: Re: Anothe DFSORT question (EXPMAX) Sent by: IBM Mainframe Discussion List <[email protected]> W dniu 2014-08-05 11:23, Elardus Engelbrecht pisze: > Radoslaw Skorupka wrote: > >> EXPMAX Specifies the maximum total amount of available storage to be used at any one time by all Hipersorting, memory object sorting, and dataspace sorting applications. >> Is it the limit for all concurrently running DFsort jobs/tasks or it is per job limitation? > Hmmm, interesting question, but see this note (DFSORT Application Programming Guide): > > [snip] > > So, it seemed that whatever the limit is, DFSORT will check it anyways and all jobs are checking each other's usage. If one job is hogging storage, others will have to wait, reduce their demand or use other storage methods. > > Is the question related to a problem you're having? > Yes. I observed excessive paging (and OLTP problems) when some DB2 REORG job runs. REORG does use DFsort under the cover. I limited the job using MEMLIMIT (and REGION) in a jobcard, but DFsort was smarter: instead of 64-bit Memory Objcects it used Hiperspaces. The result was as before: excessive paging. We talk aout tens of gigabytes used by single job. Regards -- Radoslaw Skorupka Lodz, Poland -- Treść tej wiadomości może zawierać informacje prawnie chronione Banku przeznaczone wyłącznie do użytku służbowego adresata. Odbiorcą może być jedynie jej adresat z wyłączeniem dostępu osób trzecich. Jeżeli nie jesteś adresatem niniejszej wiadomości lub pracownikiem upoważnionym do jej przekazania adresatowi, informujemy, że jej rozpowszechnianie, kopiowanie, rozprowadzanie lub inne działanie o podobnym charakterze jest prawnie zabronione i może być karalne. Jeżeli otrzymałeś tę wiadomość omyłkowo, prosimy niezwłocznie zawiadomić nadawcę wysyłając odpowiedź oraz trwale usunąć tę wiadomość włączając w to wszelkie jej kopie wydrukowane lub zapisane na dysku. This e-mail may contain legally privileged information of the Bank and is intended solely for business use of the addressee. This e-mail may only be received by the addressee and may not be disclosed to any third parties. If you are not the intended addressee of this e-mail or the employee authorized to forward it to the addressee, be advised that any dissemination, copying, distribution or any other similar activity is legally prohibited and may be punishable. If you received this e-mail by mistake please advise the sender immediately by using the reply facility in your e-mail software and delete permanently this e-mail including any copies of it either printed or saved to hard drive. mBank S.A. z siedzibą w Warszawie, ul. Senatorska 18, 00-950 Warszawa, www.mBank.pl, e-mail: [email protected] Sąd Rejonowy dla m. st. Warszawy XII Wydział Gospodarczy Krajowego Rejestru Sądowego, nr rejestru przedsiębiorców KRS 0000025237, NIP: 526-021-50-88. Według stanu na dzień 01.01.2014 r. kapitał zakładowy mBanku S.A. (w całości wpłacony) wynosi 168.696.052 złote. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN Unless stated otherwise above: IBM United Kingdom Limited - Registered in England and Wales with number 741598. Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
