Fix bug in market driven queue iteration#4701
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JamesMurkin merged 8 commits intomasterfrom Feb 20, 2026
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The CandidateGangIterator assumes that iterators it was passed were ordered - Evicted jobs - Non-evicted jobs So if it ever saw a non-evicted job, it could them just drop the whole queue when `OnlyYieldEvicted` was true However in market based scheduling, that assumption does not hold true and you can get evicted and non-evicted jobs in a mixed ordering This meant if we ever hit something that caused `OnlyYieldEvicted` when using market based scheduling, you could end up preempting many (or all) evicted jobs, depending on the job ordering - as the CandidateGangIterator stopped considering the queue as soon as it saw a non-evicted job Now I've pushed that logic down through the iterator stack - as they are better placed to make the right assumptions - I've also removed the logic about OnlyYieldEvicted dotted all over CandidateGangIterator and it is now contained to their OnlyYieldEvicted/OnlyYieldEvictedForQueue functions Signed-off-by: JamesMurkin <jamesmurkin@hotmail.com>
Signed-off-by: JamesMurkin <jamesmurkin@hotmail.com>
JamesMurkin
commented
Feb 20, 2026
| }, | ||
| PriorityFactorByQueue: map[string]float64{"A": 1, "B": 1}, | ||
| }, | ||
| "reschedules evicted jobs if scheduling limits hit": { |
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This test was what covered the original bug
Signed-off-by: JamesMurkin <jamesmurkin@hotmail.com>
Signed-off-by: JamesMurkin <jamesmurkin@hotmail.com>
Signed-off-by: JamesMurkin <jamesmurkin@hotmail.com>
JamesMurkin
commented
Feb 20, 2026
| jobDbTxn := jobDb.WriteTxn() | ||
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| // Add all the initial jobs, creating runs for them | ||
| for nodeIdx, jobs := range tc.InitialRunningJobs { |
Signed-off-by: JamesMurkin <jamesmurkin@hotmail.com>
mauriceyap
approved these changes
Feb 20, 2026
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| type JobContextIterator interface { | ||
| Next() (*schedulercontext.JobSchedulingContext, error) | ||
| OnlyYieldEvicted() |
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nit: SetOnlyYieldEvicted(onlyYieldEvicted bool) would be nicer
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The CandidateGangIterator assumes that iterators it was passed were ordered
So if it ever saw a non-evicted job, it could them just drop the whole queue when
OnlyYieldEvictedwas trueHowever in market based scheduling, that assumption does not hold true and you can get evicted and non-evicted jobs in a mixed ordering
This meant if we ever hit something that caused
OnlyYieldEvictedwhen using market based scheduling, you could end up preempting many (or all) evicted jobs, depending on the job ordering - as the CandidateGangIterator stopped considering the queue as soon as it saw a non-evicted jobNow I've pushed that logic down through the iterator stack - as they are better placed to make the right assumptions