gridengine.info

It's mailing list posts like this that generate "aha!" moments for me where I realize that I've learned how to tweak SGE behavior in a new way.

Mark answered the original poster with a good suggestion for solving the particular issue at hand -- using qalter to change priority values so that a pending parallel job can rise to the top of the waitlist.

Then Mark offhandedly dropped this little comment:

... If you always want parallel jobs to go first, you can try increasing the urgency of the 'slots' complex.

I'm familiar with the Urgency Policy mechanism in Grid Engine. I've used it many times to address specific problems from a resource allocation perspective. Typically this involves something like using the urgency policy to prioritize the dispatch of pending jobs that consume expensive flexlm software license entitlements. I'm also aware from creating and modifying requestable and/or consumable resources that all of the resource attributes listed in the SGE complex have an urgency parameter associated with them that defaults to 0.

I just hadn't really put it all together until Mark's offhand aside. It's not complicated at all, just ... elegant. Associating urgency entitlements with the "slot" complex means that jobs that need more "slots" will gain additional entitlements and thus rise up through the pending list. Since parallel jobs naturally consume more slots than serial tasks, the end results is that parallel jobs become "more important" in the scheduler mechanism than non-parallel jobs.

I'm guessing not many people have a global "parallel jobs are always more important than serial jobs" use case requirement but for those that do this could be a neat trick.