On 01/21/2015 11:07 AM, Lipari, Don wrote:
-----Original Message-----
From: Bill Wichser [mailto:b...@princeton.edu]
Sent: Wednesday, January 21, 2015 5:20 AM
To: slurm-dev
Subject: [slurm-dev] fairshare allocations
The algorithm I use is fairtree under 14.11 but I believe that my
question relates to any method.
As a University, we have many investments into a given cluster. At the
most simplistic level, lets assume there are but two two allocations.
The method I have been using is to assign a value, as a percentage of
ownership, to the various ACCOUNTs such that when summed across all
accounts, they add to 100.
So chemistry might have a fairshare value of 20 as they contributed 20%
of the funding. Physics has a value of 10. And so forth, with many
having a fairshare value of 1 since no money was contributed.
In the past, I simply assigned either a fairshare value of parent to the
users or assigned them a value of 1.
So lets take a user, call him Bill, who has a fairshare value of 1 under
the account=chem. It appears to me that this 1 share is actually a 1
share of the total and not a 1 share of what the account=chem owns. Am
I reading this correctly here?
A share of 1 for Bill is a share of the total shares assigned to users
(or accounts) under the chem account. Chem can have 1000 users, each with
1 share, but chem users' combined usage of the system will be throttled
to 20% based on job priorities calculated by the fair-share factor.
That works both ways: if only one user from chem is submitting jobs, that
user can receive 20% of the resources of the cluster, even though they have
only one share of chem.
The most common practice is to assign a share of 1 to every user in an
account. You can assign greater share values to users who are entitled
to more than their peers.
Don Lipari
Thanks,
Bill
So that was my expectation. But lets look at this account, truncated,
with a user with a fairshare of 20 (using sshare -a -l -A ee -p)
Account|User|Raw Shares|Norm Shares|Raw Usage|Norm Usage|Effectv
Usage|FairShare|Level FS|GrpCPUMins|CPURunMins|
ee||261|0.218227|189272064|0.047197|0.047197||4.623757||50912|
ee|user1|1|0.009091|24151307|0.006022|0.127601|0.771261|0.071245||24605|
ee|user2|1|0.009091|652289|0.000163|0.003446|0.780059|2.637872||0|
ee|user3|25|0.227273|15684228|0.003911|0.082866|0.781525|2.742652||0|
...
So ee as an account gets fairshare=261 and gets a 0.218227 normalized
share count.
A user underneath gets the expected 0.009091 normalized shares since
there are a lot of fairshare=1 users there. The user3 gets basically
25x this value as the fairshare for user3=25
Yet the normalized shares is actually MORE than the normalized shares
for the account as a whole. What should I make of this?
Bill
