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https://issues.apache.org/jira/browse/HADOOP-12412?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Akira AJISAKA updated HADOOP-12412:
-----------------------------------
    Target Version/s:   (was: 2.7.3)
            Priority: Major  (was: Critical)

As Michael mentioned, reduced the priority and removed the target version.

> Concurrency in FileSystem$Cache is very broken
> ----------------------------------------------
>
>                 Key: HADOOP-12412
>                 URL: https://issues.apache.org/jira/browse/HADOOP-12412
>             Project: Hadoop Common
>          Issue Type: Bug
>          Components: fs
>    Affects Versions: 2.7.0
>            Reporter: Michael Harris
>            Assignee: Michael Harris
>         Attachments: HADOOP-12412.patch, HADOOP-12412.patch
>
>
> The FileSystem cache uses a mild amount of concurrency to protect the cache 
> itself, but does nothing to prevent multiple of the same filesystem from 
> being constructed and initialized simultaneously.  At best, this leads to 
> potentially expensive wasted work.  At worst, as is the case for Spark, it 
> can lead to deadlocks/livelocks, especially when the same configuration 
> object is passed into both calls.  This should be refactored to use a results 
> cache approach (reference Java Concurrency in Practice chapter 5 section 6 
> for an example of how to do this correctly), which will be both 
> higher-performance and safer.



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