[slurm-users] FairShare
Paul Edmon
pedmon at cfa.harvard.edu
Wed Dec 2 18:26:08 UTC 2020
Yup, our doc is for the classic fairshare not for fairtree.
Thanks for the kudos on the doc by the way. We are glad it is useful.
-Paul Edmon-
On 12/2/2020 12:45 PM, Ryan Cox wrote:
> That is not for Fair Tree, which is what Micheal asked about.
>
> Ryan
>
> On 12/2/20 10:32 AM, Renfro, Michael wrote:
>>
>> Yesterday, I posted https://docs.rc.fas.harvard.edu/kb/fairshare/
>> <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdocs.rc.fas.harvard.edu%2Fkb%2Ffairshare%2F&data=04%7C01%7Crenfro%40tntech.edu%7Cc23f89dcb97743ee5eda08d8960679ed%7C66fecaf83dc04d2cb8b8eff0ddea46f0%7C1%7C1%7C637424301864169250%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C2000&sdata=%2FnB4ivZeDNrVZiaeupFnAj86oQLOhMu1%2FK6YiuBxTB8%3D&reserved=0>in
>> response to a similar question. If you want the simplest general
>> explanation for FairShare values, it's that they range from 0.0 to
>> 1.0, values above 0.5 indicate that account or user has used less
>> than their share of the resource, and values below 0.5 indicate that
>> that account or user has used more than their share of the resource.
>>
>> Since all your users have the same RawShares value and are entitled
>> to the same share of the resource, you can see that bdehaven has the
>> most RawUsage and the lowest FairShare value, followed by ajoel and
>> xtsao with almost identical RawUsage and FairShare, and finally
>> ahantau with very little usage and the highest FairShare value.
>>
>> We use FairShare here as the dominant factor in priorities for queued
>> jobs: if you're a light user, we bump up your priority over heavier
>> users, and your job starts quicker than those for heavier users,
>> assuming all other job attributes are equal.
>>
>> All these values are relative: in our setup, we'd bump ahantau's
>> pending jobs ahead of the others, and put bdehaven's at the end. But
>> if root needed to run a job outside the sray account, they'd get an
>> enormous bump ahead since the sray account has used far more than its
>> fair share of the resource.
>>
>> *From: *slurm-users <slurm-users-bounces at lists.schedmd.com>
>> *Date: *Wednesday, December 2, 2020 at 11:23 AM
>> *To: *slurm-users at lists.schedmd.com <slurm-users at lists.schedmd.com>
>> *Subject: *Re: [slurm-users] FairShare
>>
>> *External Email Warning*
>>
>> *This email originated from outside the university. Please use
>> caution when opening attachments, clicking links, or responding to
>> requests.*
>>
>> ------------------------------------------------------------------------
>>
>> I've read the manual and I re-read the other link. What they boil
>> down to is Fair Share is calculated based on a recondite "rooted
>> plane tree", which I do not have the background in discrete math to
>> understand.
>>
>> I'm hoping someone can explain it so my little kernel can understand.
>>
>> ------------------------------------------------------------------------
>>
>> *From:*slurm-users <slurm-users-bounces at lists.schedmd.com> on behalf
>> of Micheal Krombopulous <MichealKrombopulous at outlook.com>
>> *Sent:* Wednesday, December 2, 2020 9:32 AM
>> *To:* slurm-users at lists.schedmd.com <slurm-users at lists.schedmd.com>
>> *Subject:* [slurm-users] FairShare
>>
>> Can someone tell me how to calculate fairshare (under fairtree)? I
>> can't figure it out. I would have thought it would be the same score
>> for all users in an account. E.g., here is one of my accounts:
>>
>> Account User RawShares NormShares RawUsage NormUsage
>> EffectvUsage LevelFS FairShare
>> -------------------- ---------- ---------- ----------- -----------
>> ----------- ------------- ---------- ----------
>> root 0.000000 611349 1.000000
>> root root 1 0.076923 0
>> 0.000000 0.000000 inf 1.000000
>> sray 1 0.076923
>> 30921 0.505582 0.505582 0.152147
>> sray phedge 1 0.050000 0
>> 0.000000 0.000000 inf 0.181818
>> sray raab 1 0.050000 0
>> 0.000000 0.000000 inf 0.181818
>> sray benequist 1 0.050000 0
>> 0.000000 0.000000 inf 0.181818
>> sray bosch 1 0.050000 0
>> 0.000000 0.000000 inf 0.181818
>> sray rjenkins 1 0.050000 0
>> 0.000000 0.000000 inf 0.181818
>> sray esmith 1 0.050000 0
>> 0.000000 0.000000 1.7226e+07 0.054545
>> sray gheinz 1 0.050000 0
>> 0.000000 0.000000 1.9074e+14 0.072727
>> sray jfitz 1 0.050000 0
>> 0.000000 0.000000 8.0640e+20 0.081818
>> sray ajoel 1 0.050000 42449
>> 0.069465 0.137396 0.363913 0.018182
>> sray jmay 1 0.050000 0
>> 0.000000 0.000000 inf 0.181818
>> sray aferrier 1 0.050000 0
>> 0.000000 0.000000 inf 0.181818
>> sray bdehaven 1 0.050000 225002
>> 0.367771 0.727420 0.068736 0.009091
>> sray msmythe 1 0.050000 0
>> 0.000000 0.000000 inf 0.181818
>> sray gfink 1 0.050000 0
>> 0.000000 0.000000 2.0343e+05 0.045455
>> sray ahantau 1 0.050000 31
>> 0.000051 0.000102 491.737549 0.036364
>> sray hmiller 1 0.050000 0
>> 0.000000 0.000000 inf 0.181818
>> sray ttinker 1 0.050000 0
>> 0.000000 0.000000 1.4798e+13 0.063636
>> sray wcooper 1 0.050000 0
>> 0.000000 0.000000 inf 0.181818
>> sray xtsao 1 0.050000 41734
>> 0.068296 0.135083 0.370143 0.027273
>> sray xping 1 0.050000 0
>> 0.000000 0.000000 1.9833e+24 0.090909
>>
>
> --
> Ryan Cox
> Director
> Office of Research Computing
> Brigham Young University
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