[
https://issues.apache.org/jira/browse/YARN-624?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13662352#comment-13662352
]
Robert Joseph Evans commented on YARN-624:
------------------------------------------
Storm is a real-time stream processing system. We are working on porting this
to run on YARN. Storm will process one or more streams of data using a logical
DAG of processing nodes called a topology. This topology runs in spawned
processes. If there are not enough processes to run a topology there is no
point in launching any of the processes. Hence the need for gang scheduling.
It is a very simple gang scheduling use case currently. When a new topology is
submitted we want to request enough resources to to run that topology. If a
node goes down, we are going to request enough resources to replace it, so we
can get up and running again ASAP. When a topology is killed we want to
release those resources.
Long term we would like to make sure that the different containers are close to
each other from a network topology perspective. We don't care which node or
rack the containers are on, but we do care that they are all on the same
node/rack as the other containers.
> Support gang scheduling in the AM RM protocol
> ---------------------------------------------
>
> Key: YARN-624
> URL: https://issues.apache.org/jira/browse/YARN-624
> Project: Hadoop YARN
> Issue Type: Sub-task
> Components: api, scheduler
> Affects Versions: 2.0.4-alpha
> Reporter: Sandy Ryza
> Assignee: Sandy Ryza
>
> Per discussion on YARN-392 and elsewhere, gang scheduling, in which a
> scheduler runs a set of tasks when they can all be run at the same time,
> would be a useful feature for YARN schedulers to support.
> Currently, AMs can approximate this by holding on to containers until they
> get all the ones they need. However, this lends itself to deadlocks when
> different AMs are waiting on the same containers.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira
