On 02/10/2014 10:10 AM, Uri Schneider wrote:
With GROUP_AUTOREGROUP, after all groups have negotiated for resources, subject to their quotas, if there are any unmatched slots left over, there is an additional negotiation round. In this final round, the accounting groups are ignored, all the submitters with idle jobs (from all groups) effectively form a one new, ad-hoc group, and negotiate within that, according to their user priorities.
With GROUP_ACCEPT_SURPLUS, there is not an additional negotiation round. The negotiator assumes that all jobs will match all machines, and predicts how many resources each group will consume. If any group has GROUP_ACCEPT_SURPLUS, and demand above quota, and the prediction shows that there will be idle jobs, the effective quota for that group is temporarily raised by this amount for the negotiation round. This additional surplus quota is handed out to groups proportionally to their original quota assignment. Then, negotiation is run as usual.