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https://issues.apache.org/jira/browse/YARN-8833?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16690937#comment-16690937
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Hudson commented on YARN-8833:
------------------------------

FAILURE: Integrated in Jenkins build Hadoop-trunk-Commit #15456 (See 
[https://builds.apache.org/job/Hadoop-trunk-Commit/15456/])
YARN-8833. Avoid potential integer overflow when computing fair shares. (wwei: 
rev d027a24f0349b60efa5125c330058f123771748f)
* (edit) 
hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/TestComputeFairShares.java
* (edit) 
hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/policies/ComputeFairShares.java


> Avoid potential integer overflow when computing fair shares
> -----------------------------------------------------------
>
>                 Key: YARN-8833
>                 URL: https://issues.apache.org/jira/browse/YARN-8833
>             Project: Hadoop YARN
>          Issue Type: Bug
>          Components: fairscheduler
>            Reporter: liyakun
>            Assignee: liyakun
>            Priority: Major
>             Fix For: 3.3.0
>
>         Attachments: YARN-8833.1.patch, YARN-8833.2.patch, YARN-8833.3.patch, 
> YARN-8833.patch
>
>
> When use w2rRatio compute fair share, there may be a chance triggering the 
> problem of Int overflow, and entering an infinite loop.
> Since the compute share thread holds the writeLock, it may blocking 
> scheduling thread.
> This issue occurs in a production environment with 8500 nodes. And we have 
> already fixed it.
>  
> added 2018-10-29: elaborate the problem 
> /**
>  * Compute the resources that would be used given a weight-to-resource ratio
>  * w2rRatio, for use in the computeFairShares algorithm as described in #
>  */
>  private static int resourceUsedWithWeightToResourceRatio(double w2rRatio,
>  Collection<? extends Schedulable> schedulables, String type) \{ int 
> resourcesTaken = 0; for (Schedulable sched : schedulables) \{ int share = 
> computeShare(sched, w2rRatio, type); resourcesTaken += share; }
> return resourcesTaken;
>  }
> The variable resourcesTaken is an integer type. And it also is accumulated 
> value of result of
> computeShare(Schedulable sched, double w2rRatio,String type) which is a value 
> between the min share and max share of a queue.
> For example, when there are 3 queues, each has min share = max share = 
> Integer.MAX_VALUE, the resourcesTaken will be out of Integer bound, and it 
> will be a negative number.
> when resourceUsedWithWeightToResourceRatio(double w2rRatio, Collection<? 
> extends Schedulable> schedulables, String type) return a negative number, the 
> loop in 
> computeSharesInternal() may never out which got the scheduler lock.
>  
> //org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.policies.ComputeFairShares
> while (resourceUsedWithWeightToResourceRatio(rMax, schedulables, type)
>  < totalResource)
> { rMax *= 2.0; }
> This may blocking scheduling thread.



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