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-boun...@lists.schedmd.com>
*Date: *Wednesday, December 2, 2020 at 11:23 AM
*To: *slurm-users@lists.schedmd.com <slurm-users@lists.schedmd.com>
*Subject: *Re: [slurm-users] FairShare
*External Email Warning*
*This email originated from outside the university. Please use
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------------------------------------------------------------------------
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-boun...@lists.schedmd.com> on behalf
of Micheal Krombopulous <michealkrombopul...@outlook.com>
*Sent:* Wednesday, December 2, 2020 9:32 AM
*To:* slurm-users@lists.schedmd.com <slurm-users@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
