The reason for the difference in runtimes must be simple: the system that has the GRS Lock structure in its local CPC has much faster access to it. We see the same with the CA-DISK IXMAINT function that als does massive catalog searches.
Kees. > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On > Behalf Of Jesse 1 Robinson > Sent: 06 April, 2017 17:56 > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: Re: RLS for catalogs > > This goes back several years when CF and memory resources were more > expensive and less flexible than today. Think standalone CF where a > memory upgrade was a huge PITA. We had one single-system parallel > sysplex that I had refrained from turning over to GRS star. It was only > one system, after all, so what could be harm in running GRS ring? Star > would be a waste of resources, I thought. > > One particular housekeeping job ran daily in every sysplex. It did a > massive LISTCAT. We noticed that this job ran two or three times longer > (!) on this one system as compared with other sysplexes that made use of > GRS star. I could not find any plausible difference other than GRS > configuration. So on a hunch I bit the bullet and implemented GRS star. > Sure enough, the elapsed time for the big LISTCAT job immediately > dropped to a value in line with the other sysplexes. That's on a system > that did not actually share resources with any other. Not a scientific > observation, but I'm as convinced as any UFO witness ever was. > > . > . > J.O.Skip Robinson > Southern California Edison Company > Electric Dragon Team Paddler > SHARE MVS Program Co-Manager > 323-715-0595 Mobile > 626-543-6132 Office ⇐=== NEW > robin...@sce.com > > > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On > Behalf Of Mark Zelden > Sent: Thursday, April 06, 2017 7:52 AM > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: (External):Re: RLS for catalogs > > On Wed, 5 Apr 2017 18:23:29 +0000, Jesse 1 Robinson > <jesse1.robin...@sce.com> wrote: > > >I’m curious about using CA MIM Resource Sharing within a sysplex. > >Historically I used it in the days before sysplex, before PDS/E, > >before other newfangled contraptions that depend on XCF for > >serialization. We still use MIA for tape allocation across sysplexes > and across data centers. What does MIM offer for ENQ within a sysplex? > > If it is a basic sysplex, MIM (with CTCs) runs circles around GRS RING > in terms of performance. If you only have 2 systems it probably doesn't > matter, but as soon as you have 3 more systems you can really notice the > difference. > > *disclaimer* It has been quite a number of years since I have been at a > GRS RING shop with 3 or more systems but I recall a CA-1 scratch run > taking many hours due to the cross system ENQs then my client switched > to MIM and the scratch run ran in probably half the time. The > improvement in time logon to TSO and get to the ISPF main menu was very > noticeable. > > For a parallel sysplex where the scope of sharing is just withing the > sysplex, I don't know why anyone would use MIM over GRS these days. > Also, with the cheaper cost of ICF engines and inexpensive memory, I > would think the cost would at least be similar to licensing MIM. > > Regards, > > Mark > -- > Mark Zelden - Zelden Consulting Services - z/OS, OS/390 and MVS ITIL v3 > Foundation Certified mailto:m...@mzelden.com Mark's MVS Utilities: > http://www.mzelden.com/mvsutil.html > Systems Programming expert at > http://search390.techtarget.com/ateExperts/ > > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ******************************************************** For information, services and offers, please visit our web site: http://www.klm.com. This e-mail and any attachment may contain confidential and privileged material intended for the addressee only. If you are not the addressee, you are notified that no part of the e-mail or any attachment may be disclosed, copied or distributed, and that any other action related to this e-mail or attachment is strictly prohibited, and may be unlawful. If you have received this e-mail by error, please notify the sender immediately by return e-mail, and delete this message. Koninklijke Luchtvaart Maatschappij NV (KLM), its subsidiaries and/or its employees shall not be liable for the incorrect or incomplete transmission of this e-mail or any attachments, nor responsible for any delay in receipt. Koninklijke Luchtvaart Maatschappij N.V. (also known as KLM Royal Dutch Airlines) is registered in Amstelveen, The Netherlands, with registered number 33014286 ******************************************************** ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
