hadoop-hdfs-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Suresh Srinivas (JIRA)" <j...@apache.org>
Subject [jira] Commented: (HDFS-778) DistributedFileSystem.getFileBlockLocations() may occasionally return numeric ips as hostnames.
Date Fri, 20 Nov 2009 02:32:39 GMT

    [ https://issues.apache.org/jira/browse/HDFS-778?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12780386#action_12780386
] 

Suresh Srinivas commented on HDFS-778:
--------------------------------------

Looks like datanodes are registering with IP address as the name in registration instead of
host name. I in suspect o.a.h.net.DNS, {{InetAddress.getLocalHost().getCanonicalHostName()}}
is returning the IP address. Not sure if this is due to some java SecurityManager issue.

> DistributedFileSystem.getFileBlockLocations() may occasionally return numeric ips as
hostnames.
> -----------------------------------------------------------------------------------------------
>
>                 Key: HDFS-778
>                 URL: https://issues.apache.org/jira/browse/HDFS-778
>             Project: Hadoop HDFS
>          Issue Type: Bug
>            Reporter: Hong Tang
>
> DistributedFileSystem.getFileBlockLocations() may occasionally return numeric ips as
hostnames. This seems to be a breach of the FileSystem.getFileBlockLocation() contract:
> {noformat}
>   /**
>    * Return an array containing hostnames, offset and size of 
>    * portions of the given file.  For a nonexistent 
>    * file or regions, null will be returned.
>    *
>    * This call is most helpful with DFS, where it returns 
>    * hostnames of machines that contain the given file.
>    *
>    * The FileSystem will simply return an elt containing 'localhost'.
>    */
>   public BlockLocation[] getFileBlockLocations(FileStatus file, 
>       long start, long len) throws IOException
> {noformat}
> One (maybe minor) consequence of this issue is: When a job includes such numeric ips
in in its splits' locations, JobTracker would not be able to assign the job's map tasks local
to the file blocks.
> We should either fix the implementation or change the contract. In the latter case, JobTracker
needs to be fixed to maintain both the hostnames and ips of the TaskTrackers.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


Mime
View raw message