[
https://issues.apache.org/jira/browse/YARN-9278?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16796823#comment-16796823
]
Wilfred Spiegelenburg commented on YARN-9278:
---------------------------------------------
Thank for the update [~uranus]
I don't think that we can add a lot of tests, as it would become really
difficult to inspect the results. The three tests I can think of are:
* setting the batch value to 0 (-1 is the default and we do a tests with that).
* setting the value for the batch to something larger than the number of nodes
to show that we do not run out of the node list and somehow fail
* setting the batch value to {{#NMs -1}} (i.e. batch=4 in a 5 node cluster) and
do multiple runs. Even with bad random we should flip over the end of the list.
None of the tests should fail iterating nodes.
> Shuffle nodes when selecting to be preempted nodes
> --------------------------------------------------
>
> Key: YARN-9278
> URL: https://issues.apache.org/jira/browse/YARN-9278
> Project: Hadoop YARN
> Issue Type: Sub-task
> Components: fairscheduler
> Reporter: Zhaohui Xin
> Assignee: Zhaohui Xin
> Priority: Major
> Attachments: YARN-9278.001.patch, YARN-9278.002.patch,
> YARN-9278.003.patch
>
>
> We should *shuffle* the nodes to avoid some nodes being preempted frequently.
> Also, we should *limit* the num of nodes to make preemption more efficient.
> Just like this,
> {code:java}
> // we should not iterate all nodes, that will be very slow
> long maxTryNodeNum =
> context.getPreemptionConfig().getToBePreemptedNodeMaxNumOnce();
> if (potentialNodes.size() > maxTryNodeNum){
> Collections.shuffle(potentialNodes);
> List<FSSchedulerNode> newPotentialNodes = new ArrayList<FSSchedulerNode>();
> for (int i = 0; i < maxTryNodeNum; i++){
> newPotentialNodes.add(potentialNodes.get(i));
> }
> potentialNodes = newPotentialNodes;
> {code}
>
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
