hadoop-hdfs-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "jinglong.liujl (JIRA)" <j...@apache.org>
Subject [jira] Commented: (HDFS-1325) DFSClient(DFSInputStream) release the persistent connection with datanode when no data have been read for a long time
Date Wed, 04 Aug 2010 05:26:18 GMT

    [ https://issues.apache.org/jira/browse/HDFS-1325?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12895149#action_12895149
] 

jinglong.liujl commented on HDFS-1325:
--------------------------------------

    Thanks for your reply. 
    I think hbase client (In fact, it's region server) should use HDFS as general file system,
It holds HDFS input stream like a simple file handle.Network connection between DFSClient
and DataNode should be transparent to them. 
    As a platform,  we should handle these resources to make platform more robust,  right
? 
    From another point´╝î HBase client should close file handle (input stream) in the right
time.

> DFSClient(DFSInputStream) release the persistent connection with datanode when no data
have been read for a long time
> ---------------------------------------------------------------------------------------------------------------------
>
>                 Key: HDFS-1325
>                 URL: https://issues.apache.org/jira/browse/HDFS-1325
>             Project: Hadoop HDFS
>          Issue Type: Improvement
>          Components: hdfs client
>            Reporter: jinglong.liujl
>             Fix For: 0.20.3
>
>         Attachments: dfsclient.patch, toomanyconnction.patch
>
>
> When you use Hbase over hadoop. We found during scanning over a large table ( which has
many regions and each region has many store files), there're too many connections has been
kept between regionserver (act as DFSClient) and datanode.  Even if the store file has been
complete to scanning, the connections can not be closed.
> In our cluster, too many extra connections cause too many system resource has been wasted,
which cause system cpu on region server reach to a high level, then bring this region server
down.
> After investigating, we found the number of active connection is very small, and the
most connection is idle. We add a timeout checker thread into DFSClient, to close this connection.

-- 
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