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https://issues.apache.org/jira/browse/MESOS-3912?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15003845#comment-15003845
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Alexander Rukletsov commented on MESOS-3912:
--------------------------------------------
Here is the algorithm we propose for rescinding.
A quota request for role {{r}} for {{X}} resources comes in. There are {{numF}}
frameworks in {{r}}. Let {{T}} be the total number of rescinded resources.
* while (there are agents with outstanding offers) do:
** if (({{T}} contains {{X}}) {{AND}} ({{visited agents count}} >= {{numF}})
{{break}};
** fetch an agent {{a}} with outstanding offers;
** rescind all outstanding offers from {{a}};
** update {{T}};
* end.
The built-in allocator currently allocates all free resources on an agent to a
single framework. Rescinding offers from *at least* {{numF}} agents makes it
possible (but not necessarily happening, remember fair shares) that each
framework in {{r}} gets an offer. Rescinding *all* offers from an agent makes
this offer bigger, which increases chances a framework will be able to use the
offer.
> Rescind offers in order to satisfy quota
> ----------------------------------------
>
> Key: MESOS-3912
> URL: https://issues.apache.org/jira/browse/MESOS-3912
> Project: Mesos
> Issue Type: Task
> Components: master
> Reporter: Alexander Rukletsov
> Assignee: Alexander Rukletsov
> Labels: mesosphere
>
> When a quota request comes in, we may need to rescind a certain amount of
> outstanding offers in order to satisfy it. Because resources are allocated in
> the allocator, there can be a race between rescinding and allocating. This
> race makes it hard to determine the exact amount of offers that should be
> rescinded in the master.
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