Thread: Advance reservations

Originally posted by: gskouson, Wed Oct 25, 2006 5:45 pm

At times, advance reservations don't seem to work like I expect them to.

This morning, I had a job that I had targeted to a specific node with the -m flag on bsub. Even though the node was empty, the job wouldn't start. The reason in the bjobs -lp output said that it couldn't start due to a reservation on the node. The brsvs command showed that no reservations should have been in place on the node until the next day and the job had a runlimit of 10 minutes.

We've used advance reservations to ensure that a few nodes are available for short jobs during the day, so the reservations have been for a time from 6:59am - 7:00am on weekdays. These reservations have been in place for months and seemed to be working in the past, but for some reason the scheduler was a bit confused this morning.

I created another reservation for 7:00am - 7:01am and removed the previous reservation and the jobs were allowed to start.

I resubmitted the job to make sure that it was still working and all seems normal again.

Does anyone else use advance reservations? Do you experience problems with them working as you hoped?

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Gary Skouson

Originally posted by: wlu, Wed Nov 22, 2006 7:47 pm

Advanced reservation has been used by many people in the LSF HPC community. For your case, it could be a special situation or a bug. If it happens again, suggest contacting Platform support and have them to troubleshoot.

William

Originally posted by: lorenw, Tue Nov 28, 2006 9:32 pm

We use advance reservations from time to time to handle special situations where users need to do something special/unusual requiring resources that need to be guaranteed available and have not had any problems thus far.
Hurricane modelling comes to mind as a situation where real-time constraints have blown us in the direction to use advance reservation; so far so good.
Loren

Loren Watterson
UNC-Chapel Hill
ITS Research Computing Group