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https://issues.apache.org/jira/browse/HADOOP-10852?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Benoy Antony updated HADOOP-10852:
----------------------------------

    Affects Version/s: 2.5.0
               Status: Patch Available  (was: Open)

> NetgroupCache is not thread-safe
> --------------------------------
>
>                 Key: HADOOP-10852
>                 URL: https://issues.apache.org/jira/browse/HADOOP-10852
>             Project: Hadoop Common
>          Issue Type: Bug
>          Components: security
>    Affects Versions: 2.4.1, 2.5.0
>            Reporter: Benoy Antony
>            Assignee: Benoy Antony
>         Attachments: HADOOP-10852.patch
>
>
> _NetgroupCache_ internally uses two _ConcurrentHashMap_s and a boolean 
> variable to signal updates on one of the _ConcurrentHashMap_s 
> None of the functions are synchronized  and hence is possible to have 
> unexpected results due to race condition between different threads.
> As an example, consider the following sequence:
> Thread1 :
> {{add}} a group
> {{netgroupToUsersMap}} is updated.
> {{netgroupToUsersMapUpdated}} is set to true.
> Thread 2:
> calls {{getNetgroups}} for a user
> Due to re-ordering, {{netgroupToUsersMapUpdated=true}} is visible, but 
> updates in {{netgroupToUsersMap}} is not visible.
> Does a wrong update with older {{netgroupToUsersMap}} values. 



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