[
https://issues.apache.org/jira/browse/YARN-1969?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13996444#comment-13996444
]
Maysam Yabandeh commented on YARN-1969:
---------------------------------------
[~kkambatl], you are right. The title of the jira is misleading. The jira
description talks about the jobs that are about to finish and their estimated
endtime but the title indicates deadline. I guess the confusion came from the
name "earliest deadline first" algorithm cited in the jira description. What we
had in mind was a variation of the algorithm that a) takes other parameters
into account, b) it is not necessarily tied to deadline.
> Fair Scheduler: Add policy for Earliest Deadline First
> ------------------------------------------------------
>
> Key: YARN-1969
> URL: https://issues.apache.org/jira/browse/YARN-1969
> Project: Hadoop YARN
> Issue Type: Improvement
> Reporter: Maysam Yabandeh
> Assignee: Maysam Yabandeh
>
> What we are observing is that some big jobs with many allocated containers
> are waiting for a few containers to finish. Under *fair-share scheduling*
> however they have a low priority since there are other jobs (usually much
> smaller, new comers) that are using resources way below their fair share,
> hence new released containers are not offered to the big, yet
> close-to-be-finished job. Nevertheless, everybody would benefit from an
> "unfair" scheduling that offers the resource to the big job since the sooner
> the big job finishes, the sooner it releases its "many" allocated resources
> to be used by other jobs.In other words, what we require is a kind of
> variation of *Earliest Deadline First scheduling*, that takes into account
> the number of already-allocated resources and estimated time to finish.
> http://en.wikipedia.org/wiki/Earliest_deadline_first_scheduling
> For example, if a job is using MEM GB of memory and is expected to finish in
> TIME minutes, the priority in scheduling would be a function p of (MEM,
> TIME). The expected time to finish can be estimated by the AppMaster using
> TaskRuntimeEstimator#estimatedRuntime and be supplied to RM in the resource
> request messages. To be less susceptible to the issue of apps gaming the
> system, we can have this scheduling limited to *only within a queue*: i.e.,
> adding a EarliestDeadlinePolicy extends SchedulingPolicy and let the queues
> to use it by setting the "schedulingPolicy" field.
--
This message was sent by Atlassian JIRA
(v6.2#6252)
