Qmgr -c 'set server est_start_time_freq ...' fails

[arungrover]

@buchmann

Presently, I use set server backfill_depth = 10, but I don’t know what else to do to enable it.

EDIT2:Actually, the present configuration seems to perform some backfilling. Testing shows that if I submit a job requiring all jobs except one and subsquently a second job requiring all nodes. Then obviously, the first job runs, while the second is queued. A third - much shorter - job requiring just the single node left by the first job can now be allowed to run - bypassing the second job. Thus, it appears that backfilling is working. But I do not see any mentioning of backfill in scheduler or server logs. Nor do I see any estimated things in qstat -f./EDIT2

Well setting backfill_depth to a positive non-zero value should turn backfilling on.

In the test scenario that you quoted do you have strict_ordering enabled? unless you have that enabled, your second job will not become a “top job” and backfilling will not happen. Also, setting strict_ordering is one way of making a job top job, there can be other ways of doing the same thing.
The reason that you see your third job running is because when scheduler figured the second job could not run it moved to the next job which it wants to run.

To test backfilling I’d suggest you make the walltime of your third job same or greater than that of the first job. If backfilling happens then your third job will not run because it’s node solution will clash with the estimated node solution of your second job (Top job). But, if you modify the walltime of your third job (filler job) in such a way that it end before the first job is estimated to end then you will see this filler job getting backfilled and it will start running.

I hope I’ve not managed to confuse you