Scheduler: when evicting don't normalise actualShare #3899
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Signed-off-by: robersmi606 <robert.smith@gresearch.co.uk>
d80tb7
approved these changes
Sep 4, 2024
svc-gh-ghzonetrans-p
restored the
sendToGitHub/sched-no-div-total-cost
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svc-gh-ghzonetrans-p
restored the
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Problem
There is currently a problem when
adjustedFairShareis capped by demand.The scheduler caps
adjustedFairSharetocostat https://git.c3.zone/GR/armada/blob/69232402e78d1a420d56374415436fe15d2ebf0e/internal/scheduler/context/scheduling.go#L174However, when deciding whether to evict a job, it compares fair share to
actualShare = cost / totalCostatarmada/internal/scheduler/preempting_queue_scheduler.go
Line 132 in 6923240
If
totalCost < 1(which it often is for gpu clusters), dividing bytotalCostinflatesactualShareso that it thinksactualShareis above fair share even for fairly undemanding users. So it evicts many jobs well below fair share.Solution
Get rid of the
/ totalCostatpreempting_queue_scheduler.go#L132This simplifies things, and makes it consistent between the two places. It also stops strange behavior for non-full clusters where totalCost may we well under 1, so actualShare gets inflated, and many jobs are evicted even though the cluster isn't full.