[
https://issues.apache.org/jira/browse/YARN-311?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13807505#comment-13807505
]
Junping Du commented on YARN-311:
---------------------------------
Luke, the volatile is not enough as you cannot set capacity and
overCommitTimeout in an atomic way (even in api with two parameters). Take
following example (API in you suggested way to have two parameters in set)
{code}
void setTotalCapacity(int resource, int overCommitTimeout) {
this.resource = resource;
this.overCommitTimeout = overCommitTimeout;
}
{code}
Thread 1 finished update it to (resource1 and overCommitTimeout1), thread 2
want to update it to (resource2, overCommitTimeout2) but when it just update
resource2, another thread is reading and may get a mixed result (resource1,
overCommitTimeout2) which should never appear in user's operation. I think
putting a synchronized tag is worth it and it equals exactly the same as put
synchronized on method (even in deadlock prospective). Thoughts?
> Dynamic node resource configuration: core scheduler changes
> -----------------------------------------------------------
>
> Key: YARN-311
> URL: https://issues.apache.org/jira/browse/YARN-311
> Project: Hadoop YARN
> Issue Type: Sub-task
> Components: resourcemanager, scheduler
> Reporter: Junping Du
> Assignee: Junping Du
> Attachments: YARN-311-v10.patch, YARN-311-v1.patch,
> YARN-311-v2.patch, YARN-311-v3.patch, YARN-311-v4.patch, YARN-311-v4.patch,
> YARN-311-v5.patch, YARN-311-v6.1.patch, YARN-311-v6.2.patch,
> YARN-311-v6.patch, YARN-311-v7.patch, YARN-311-v8.patch, YARN-311-v9.patch
>
>
> As the first step, we go for resource change on RM side and expose admin APIs
> (admin protocol, CLI, REST and JMX API) later. In this jira, we will only
> contain changes in scheduler.
> The flow to update node's resource and awareness in resource scheduling is:
> 1. Resource update is through admin API to RM and take effect on RMNodeImpl.
> 2. When next NM heartbeat for updating status comes, the RMNode's resource
> change will be aware and the delta resource is added to schedulerNode's
> availableResource before actual scheduling happens.
> 3. Scheduler do resource allocation according to new availableResource in
> SchedulerNode.
> For more design details, please refer proposal and discussions in parent
> JIRA: YARN-291.
--
This message was sent by Atlassian JIRA
(v6.1#6144)
