[ 
https://issues.apache.org/jira/browse/HDFS-13990?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16652259#comment-16652259
 ] 

BELUGA BEHR edited comment on HDFS-13990 at 10/16/18 7:12 PM:
--------------------------------------------------------------

[~elgoiri] My current thought is that I'm a turkey. I believe I found the best 
path forward and submitted [^HDFS-13990.2.patch]  It's fast *and* proper *and* 
less code.  All my favorites. :)


was (Author: belugabehr):
[~elgoiri] My current thought is that I'm a turkey. I believe I found the best 
path forward and submitted [^HDFS-13990.2.patch]  It's fast *and* proper.

> Synchronization Issue With HashResolver.java
> --------------------------------------------
>
>                 Key: HDFS-13990
>                 URL: https://issues.apache.org/jira/browse/HDFS-13990
>             Project: Hadoop HDFS
>          Issue Type: Bug
>          Components: federation
>    Affects Versions: 3.2.0
>            Reporter: BELUGA BEHR
>            Assignee: BELUGA BEHR
>            Priority: Minor
>         Attachments: HDFS-13990.1.patch, HDFS-13990.2.patch
>
>
> {code:java|title=HashResolver.java}
>   private ConsistentHashRing getHashResolver(final Set<String> namespaces) {
>     int hash = namespaces.hashCode();
>     ConsistentHashRing resolver = this.hashResolverMap.get(hash);
>     if (resolver == null) {
>       resolver = new ConsistentHashRing(namespaces);
>       this.hashResolverMap.put(hash, resolver);
>     }
>     return resolver;
>   }
> {code}
> The {{hashResolverMap}} is a {{ConcurrentHashMap}} so presumably there is 
> concern here for concurrency issues.  However, there is no synchronization 
> around this method, so two threads could call {{get(hash)}} both see a 'null' 
> value and then both add two entries into the {{Map}}.  Add synchronization 
> here.



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)

---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to