hadoop-yarn-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Thomas Graves (JIRA)" <j...@apache.org>
Subject [jira] [Created] (YARN-1769) CapacityScheduler: Improve reservations
Date Fri, 28 Feb 2014 20:02:20 GMT
Thomas Graves created YARN-1769:

             Summary: CapacityScheduler:  Improve reservations
                 Key: YARN-1769
                 URL: https://issues.apache.org/jira/browse/YARN-1769
             Project: Hadoop YARN
          Issue Type: Improvement
          Components: capacityscheduler
    Affects Versions: 2.3.0
            Reporter: Thomas Graves
            Assignee: Thomas Graves

Currently the CapacityScheduler uses reservations in order to handle requests for large containers
and the fact there might not currently be enough space available on a single host.

The current algorithm for reservations is to reserve as many containers as currently required
and then it will start to reserve more above that after a certain number of re-reservations
(currently biased against larger containers).  Anytime it hits the limit of number reserved
it stops looking at any other nodes. This results in potentially missing nodes that have enough
space to fullfill the request.   

The other place for improvement is currently reservations count against your queue capacity.
 If you have reservations you could hit the various limits which would then stop you from
looking further at that node.  

The above 2 cases can cause an application requesting a larger container to take a long time
to gets it resources.  

We could improve upon both of those by simply continuing to look at incoming nodes to see
if we could potentially swap out a reservation for an actual allocation. 

This message was sent by Atlassian JIRA

View raw message