[Mauiusers] Dynamic scheduling priorities in a heterogeneous
p.millar at physics.gla.ac.uk
Wed Jul 9 13:26:28 MDT 2008
I have a technical question about what is possible with Maui (without any
code-changes to the Maui code-base). I don't know Maui well enough and I
suspect the idea is slightly off the beaten track.
In essence, I'd like to treat the cluster as heterogeneous in a job-specific
and dynamic way, and have this non-homogeniality affect Maui's scheduling.
To be slightly more specific: suppose I have a script that, when you give it a
job ID and a node ID, it returns a single number. This number gives some
measure of how desirable it is to run the given job on the particular node.
The script uses dynamically collected information, so re-running the script
with the same parameters at a later time may give different results. (For
simplicity, I'm assuming that the job-ID is sufficient and the script can
discover everything it needs to know from that).
For example, if the job ID is kept constant then the script indicates how
desirable each node is for running the job right now; if the node ID is kept
constant then the script indicates which job is best to run next (assuming no
other influences, like fair-share).
What I would to know is whether Maui provides an interface that allows its job
scheduling decision to be influenced by such a script. I'm not looking to
replace the other influences (such as fair-share), but rather include an
extra parameter that might influence Maui's choice of which job to run next;
or, if there are more free job-slots than scheduled jobs, it might influence
which node(s) a job is allocated.
Looking at section 5.2 Node Allocation:
it looks like I've two options: either use a NODEALLOCATIONPOLICY of LOCAL, or
use NODEALLOCATIONPOLICY of PRIORITY and specify the influence by defining
PRIORITYF that includes PREF.
The NODEALLOCATIONPOLICY of LOCAL looks like the more flexible approach, but
the documentation is somewhat limited. Has anyone used this approach? Would
it work for me?
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