Thanks for the replies - they will help me think about configuration changes.
On Wed, 22 Jan 2020 at 14:05, Loris Bennett <loris.benn...@fu-berlin.de> wrote: > Hi, > > We have > > PriorityDecayHalfLife=7-0 > PriorityMaxAge=7-0 > > which are the defaults. > > I don't quite understand the point below about the business of the > cluster. If the cluster isn't busy, the jobs won't need to compete and > jobs belonging to users with zero shares will still start. > > For me the half-life should be related to the maximum time limit. If I > allow jobs to run for, say, 14 days, I probably want that CPU-usage to > count against the priority for a similar period, rather than decaying > very rapidly. > > Ultimately the longer the half-life, the "fairer" the priorities will > be. However, if I have only a few serious multicore power-users, I > might want them to have a bit of an edge over hundreds of individual > users with small numbers of single-core jobs. In that case I would > shorten the half-life. > > What a good value for PriorityMaxAge is is, to my mind, even harder to > say. The longer it is, the more you reward the time spent pending. In > my setup it mainly helps jobs of owners who have used up all their > shares. As well as getting back shares through the decay of CPU-usage, > which benefits all jobs, ageing benefits individual jobs. Of course, > how much the jobs benefit depends greatly on the weight you give to > MaxAge. > > Just my 2¢ > > Loris > > Hadrian Djohari <hx...@case.edu> writes: > > > Hi Killian, > > > > We choose to penalize the users a little only for their previous busy > jobs, so we choose short turnarounds. > > PriorityDecayHalfLife=1-0 > > PriorityMaxAge=4-0 > > > > The busier the cluster, the longer should the parameters be, so the user > previous jobs will restrict the "future" ones more. > > These should be adjusted based on the actual usage and impact to the > users. > > > > Best, > > Hadrian > > > > On Wed, Jan 22, 2020 at 4:22 AM Killian Murphy < > killian.mur...@york.ac.uk> wrote: > > > > Hi all. > > > > I’m interested to learn what people are using for the following > configuration items: > > > > * PriorityDecayHalfLife > > * PriorityMaxAge > > > > and why they have chosen to set these as they have. I believe we > haven’t got these set quite right on our cluster (3-0 for both items), and > some understanding of what other people are doing with these > > settings might help us to get this right! > > > > For context, ours is a tier 3 cluster servicing mixed workloads. > > > > Thanks. > > > > Killian > > > > -- > > Killian Murphy > > Research and High Performance Computing Team Leader > > Research Software Engineer > > > > Information Services & Wolfson Atmospheric Chemistry Laboratories > > University of York > > Heslington > > York > > YO10 5DD > > +44 (0)1904 32 4753 > > > > e-mail disclaimer: http://www.york.ac.uk/docs/disclaimer/email.htm > -- > Dr. Loris Bennett (Mr.) > ZEDAT, Freie Universität Berlin Email loris.benn...@fu-berlin.de > > -- Killian Murphy Research and High Performance Computing Team Leader Research Software Engineer Information Services & Wolfson Atmospheric Chemistry Laboratories University of York Heslington York YO10 5DD +44 (0)1904 32 4753 e-mail disclaimer: http://www.york.ac.uk/docs/disclaimer/email.htm
