[
https://issues.apache.org/jira/browse/HADOOP-10448?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13980112#comment-13980112
]
Benoy Antony commented on HADOOP-10448:
---------------------------------------
>From Java Concurrency in Practice:
{panel}
To publish an object safely, both the reference to the object and the object's
state must be made visible to other threads at the same time. A properly
constructed object can be safely published by:
* Initializing an object reference from a static initializer;
* Storing a reference to it into a volatile field or AtomicReference;
* Storing a reference to it into a final field of a properly constructed
object; or
* Storing a reference to it into a field that is properly guarded by a lock.
{panel}
In this case instance of ImpersonationProvider is constructed and stored in a
volatile field. So when other threads access the volatile field, they see
properly constructed object.
> Support pluggable mechanism to specify proxy user settings
> ----------------------------------------------------------
>
> Key: HADOOP-10448
> URL: https://issues.apache.org/jira/browse/HADOOP-10448
> Project: Hadoop Common
> Issue Type: Sub-task
> Components: security
> Affects Versions: 2.3.0
> Reporter: Benoy Antony
> Assignee: Benoy Antony
> Attachments: HADOOP-10448.patch, HADOOP-10448.patch,
> HADOOP-10448.patch, HADOOP-10448.patch, HADOOP-10448.patch,
> HADOOP-10448.patch, HADOOP-10448.patch
>
>
> We have a requirement to support large number of superusers. (users who
> impersonate as another user)
> (http://hadoop.apache.org/docs/r1.2.1/Secure_Impersonation.html)
> Currently each superuser needs to be defined in the core-site.xml via
> proxyuser settings. This will be cumbersome when there are 1000 entries.
> It seems useful to have a pluggable mechanism to specify proxy user settings
> with the current approach as the default.
--
This message was sent by Atlassian JIRA
(v6.2#6252)
