Thursday, November 15, 2007


One thing which was always desirable in the batch system was to guarantee a number of jobs slots for groups, irrespective of their fairshare usage. We actually want to encourage opportunistic usage of resources, and not punish people by then refusing to run any of their jobs for a week.

However, attempts to set a soft MAXPROC limit always seemed to come to grief. Maui would block jobs beyond the soft limit, even though, as far as I could see, it had been told not to. in frustration I had to set all groups with a soft limit at the cluster size.

Today, I had a chat with the great maui guru, Steve T, who was also somewhat puzzled by maui's behaviour. He pointed out that he'd only ever set MAXJOBS, not MAXPROC. Well, I thought I would give that a whirl and it works!

So, finally we can have a system which protects some slots for VOs and groups, but allows for full opportunistic use of the cluster for everyone.

Thanks Steve!

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