Re: WLM Guidance/Suggestions ! ! !
What Kees has written is correct. My rule of thumb is the faster the CP the lower the velocity. With CPU upgrades I typically revise the velocity down. It would help us if you would post a snapshot of the SUM report in RMF III, then we have all the info and not just a tiny bit and we can help you more accuately. -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
Re: WLM Guidance/Suggestions ! ! !
Your problem is probably caused by the faster CPs, combined with the definition of Velocity. - Velocity in fact means that a job receives nn% of what it wants. CPU hungry jobs will therefor get much CPU if their imp os high enough. - On the 5 CP machine, the jobs probably did not 'monopolize' all the engines, leaving room for other jobs, while on the 2 CP machine they are now able to monopolize it, leaving nothing for other jobs. If the jobs are important, you can start with keeping their imp, but lowering their velocity, until they receive what you want them to, leaving capacity for other jobs. Kees. -Original Message- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of Pesce, Andy Sent: 30 January 2020 15:24 To: IBM-MAIN@LISTSERV.UA.EDU Subject: WLM Guidance/Suggestions ! ! ! I have recently replace an IBM-2828 that had 5 GP's to a newer model machine IBM-3907-ZR1 with only 2 GP's. Does anyone know of a guide or paper or something that might have some things to look at or modify when reducing the number of GP's. I have 2 classes of service for my batch jobs.One runs with a velocity and importance of "2". This is a grouping we have called our critical path jobs that are time sensitive and they must run.Then I have another class that runs with a velocity, but has an importance of "3". This grouping is for jobs that are not time sensitive, but they do need to run and get service. The behavior that I am seeing is that the class that has the IMP-2 dominates the box until they are finished. The other jobs will sit in the initiator for 30mins up to an hour and I never see any service being consumed. Then once the IMP-2 jobs finish, then the other jobs will take off and get service. My goal is to have the IMP-2 take 80-90%, but give the IMP-3 a small chunk of service. The only way that I have been able to come close is to make both classes the same importance level. Any thoughts, documents, white papers, experiences with dealing with the reduction of GP's would be greatly appreciated. -- 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
Re: WLM Guidance/Suggestions ! ! !
Cheryl hasn't piped in for awhile. Widely published and referenced tuning metrics and Goal Tender software available at www.watsonwalker.com In a message dated 1/30/2020 10:36:33 PM Central Standard Time, and...@blackhillsoftware.com writes: >From my experience on systems with limited CPs (albeit some time ago): -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
Re: WLM Guidance/Suggestions ! ! !
From my experience on systems with limited CPs (albeit some time ago): - Velocities need to be reviewed. Achievable velocities might be much lower than on a system with more CPs. - It is critical that goals are achievable. The goal tells WLM when it can take resources away from high importance work to allow lower importance work to run. If high importance work isn't achieving its velocity goal, WLM will not allow lower importance work to take CPU time from higher importance work. - Related to the previous point, it is better to under specify velocities than over specify. Specify the minimum velocity required to complete the work in time. - I had good success with multi period batch service classes. This allowed small lower importance jobs (small enough that they wouldn't significantly impact more important work) to complete while the important work was prioritized over larger jobs. - Multi period service classes made response time goals practical for the first periods and reduced the need to figure out velocities. - Discretionary worked great for batch work *BUT* you need to have enough work running in discretionary. If you have e.g. 5% of work in discretionary it's likely to get starved. If it's 20-30% i.e. your CPU intensive batch, it will run and simplify WLM management - WLM knows exactly where the CPU resources should come from to handle workload fluctuations. - WLM also had a function where it would cap higher importance work that was over achieving goals to allocate more CPU to discretionary. This helped control high importance, CPU intensive work that WLM had difficulty managing with dispatching priorities. I think there have been changes in this area so I don't know whether this is still applicable. I think my service classes for batch ended up something like: Low importance batch: Period 1: Long enough for small jobs to complete, response time goal. Period 2: Discretionary High Importance Batch: Period 1: Small jobs, response time goal Period 2: Most other work response time or velocity goal (can't remember) Period 3: Monsters, discretionary. This worked well. High importance batch jobs in discretionary is a bit controversial, but it worked great for me on a system with limited CPs. I don't know why (maybe the MTTW dispatching in discretionary?) but when I implemented it the overnight batch run time reduced 15-20%. I hope this helps, Andrew Rowley On 31/01/2020 1:23 am, Pesce, Andy wrote: I have recently replace an IBM-2828 that had 5 GP's to a newer model machine IBM-3907-ZR1 with only 2 GP's. Does anyone know of a guide or paper or something that might have some things to look at or modify when reducing the number of GP's. I have 2 classes of service for my batch jobs.One runs with a velocity and importance of "2". This is a grouping we have called our critical path jobs that are time sensitive and they must run.Then I have another class that runs with a velocity, but has an importance of "3". This grouping is for jobs that are not time sensitive, but they do need to run and get service. The behavior that I am seeing is that the class that has the IMP-2 dominates the box until they are finished. The other jobs will sit in the initiator for 30mins up to an hour and I never see any service being consumed. Then once the IMP-2 jobs finish, then the other jobs will take off and get service. My goal is to have the IMP-2 take 80-90%, but give the IMP-3 a small chunk of service. The only way that I have been able to come close is to make both classes the same importance level. Any thoughts, documents, white papers, experiences with dealing with the reduction of GP's would be greatly appreciated. -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN -- Andrew Rowley Black Hill Software -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
Re: WLM Guidance/Suggestions ! ! !
For a start you need to review your goals. You mentioned Velocity - and that would be a prime one where some adjustment will be required. Check the velocity attained as it varies over a period of time and adjust the goal to be close to it (unless you want to give it a bonus or punish it). If you really want to dole out specific proportions of the CPU you're probably talking about Resource Groups, though I'd not be that keen on that approach. Cheers, Martin Martin Packer zChampion, Systems Investigator & Performance Troubleshooter, IBM +44-7802-245-584 email: martin_pac...@uk.ibm.com Twitter / Facebook IDs: MartinPacker Blog: https://www.ibm.com/developerworks/mydeveloperworks/blogs/MartinPacker Podcast Series (With Marna Walle): https://developer.ibm.com/tv/mpt/or https://itunes.apple.com/gb/podcast/mainframe-performance-topics/id1127943573?mt=2 Youtube channel: https://www.youtube.com/channel/UCu_65HaYgksbF6Q8SQ4oOvA From: "Pesce, Andy" To: IBM-MAIN@LISTSERV.UA.EDU Date: 30/01/2020 14:24 Subject: [EXTERNAL] WLM Guidance/Suggestions ! ! ! Sent by:IBM Mainframe Discussion List I have recently replace an IBM-2828 that had 5 GP's to a newer model machine IBM-3907-ZR1 with only 2 GP's. Does anyone know of a guide or paper or something that might have some things to look at or modify when reducing the number of GP's. I have 2 classes of service for my batch jobs.One runs with a velocity and importance of "2". This is a grouping we have called our critical path jobs that are time sensitive and they must run.Then I have another class that runs with a velocity, but has an importance of "3". This grouping is for jobs that are not time sensitive, but they do need to run and get service. The behavior that I am seeing is that the class that has the IMP-2 dominates the box until they are finished. The other jobs will sit in the initiator for 30mins up to an hour and I never see any service being consumed. Then once the IMP-2 jobs finish, then the other jobs will take off and get service. My goal is to have the IMP-2 take 80-90%, but give the IMP-3 a small chunk of service. The only way that I have been able to come close is to make both classes the same importance level. Any thoughts, documents, white papers, experiences with dealing with the reduction of GP's would be greatly appreciated. -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu 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 lists...@listserv.ua.edu with the message: INFO IBM-MAIN
WLM Guidance/Suggestions ! ! !
I have recently replace an IBM-2828 that had 5 GP's to a newer model machine IBM-3907-ZR1 with only 2 GP's. Does anyone know of a guide or paper or something that might have some things to look at or modify when reducing the number of GP's. I have 2 classes of service for my batch jobs.One runs with a velocity and importance of "2". This is a grouping we have called our critical path jobs that are time sensitive and they must run.Then I have another class that runs with a velocity, but has an importance of "3". This grouping is for jobs that are not time sensitive, but they do need to run and get service. The behavior that I am seeing is that the class that has the IMP-2 dominates the box until they are finished. The other jobs will sit in the initiator for 30mins up to an hour and I never see any service being consumed. Then once the IMP-2 jobs finish, then the other jobs will take off and get service. My goal is to have the IMP-2 take 80-90%, but give the IMP-3 a small chunk of service. The only way that I have been able to come close is to make both classes the same importance level. Any thoughts, documents, white papers, experiences with dealing with the reduction of GP's would be greatly appreciated. -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
