Re: [Condor-users] Disabling User Priorities

[Matt Hope <matthew.hope@xxxxxxxxx>]

On 6/30/05, Sean Looper <slooper@xxxxxxxxxxxxxxxxxxxx> wrote:
> I would like to disable the functionality that considers user priorities
> when allocating pool resources.  I would like the entire pool to choose
> jobs based solely on the Rank expression and Job Priority.  Is there a
> way for me to do this?

Yes - with a great many provisos and quid pro quos.

Search the archives for my name and you'll See a fair number of
conversations I was involved in a while back with other people wanting
the same thing.

in a nutshell
1) set the priority halflife to something really small or zero
2) ensure your job ranking does not cause changes in rank for the same
job over short time scales

The provisos are:

If you use Job Rank to order jobs a higher ranking job will *always*
preempt a lower running one. there is no way to stop this. therefore
you need at least one of:

1) well behaved users or job streams.
2) checkpoint friendly jobs

If a user is silly enough to rank a job in their queue highly (the job
priority formerly between +-20 now an int in all its glory) over one
which would have a higher machine rank then this will not get a chance
until the higher job is dealt with.

Thrashing will be horrific if you try to have a fine grained sense of
machine RANK. I suggest the tiering approach that many people use.
There has been some use of a system which links the user specified
priority to the RANK. this relies on decent user behaviour though...

Matt