hadoop-common-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Todd Lipcon (JIRA)" <j...@apache.org>
Subject [jira] Commented: (HADOOP-5713) File write fails after data node goes down
Date Thu, 04 Jun 2009 05:28:09 GMT

    [ https://issues.apache.org/jira/browse/HADOOP-5713?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12716157#action_12716157
] 

Todd Lipcon commented on HADOOP-5713:
-------------------------------------

Just wanted to drop a note to say that we've seen this problem in practice on a reasonable
size (multirack) cluster as well. We're working on getting some better data to correlate the
log messages with datanode failure events, but as far as we can tell the symptoms look identical.

Dhruba/Raghu: At this point I am relatively unfamiliar with this part of the code, but if
you guys have a good idea of how to solve this, I'm happy to dive in and try to produce a
patch in the next couple of weeks based on your guidance. Let me know.

> File write fails after data node goes down
> ------------------------------------------
>
>                 Key: HADOOP-5713
>                 URL: https://issues.apache.org/jira/browse/HADOOP-5713
>             Project: Hadoop Core
>          Issue Type: Bug
>          Components: dfs
>            Reporter: Alban Chevignard
>         Attachments: failed_write.patch
>
>
> If a data node goes down while a file is being written do HDFS, the write fails with
the following errors:
> {noformat} 
> 09/04/20 17:15:39 INFO dfs.DFSClient: Exception in createBlockOutputStream java.io.IOException:
> Bad connect ack with firstBadLink 192.168.0.66:50010
> 09/04/20 17:15:39 INFO dfs.DFSClient: Abandoning block blk_-6792221430152215651_1003
> 09/04/20 17:15:45 INFO dfs.DFSClient: Exception in createBlockOutputStream java.io.IOException:
> Bad connect ack with firstBadLink 192.168.0.66:50010
> 09/04/20 17:15:45 INFO dfs.DFSClient: Abandoning block blk_-1056044503329698571_1003
> 09/04/20 17:15:51 INFO dfs.DFSClient: Exception in createBlockOutputStream java.io.IOException:
> Bad connect ack with firstBadLink 192.168.0.66:50010
> 09/04/20 17:15:51 INFO dfs.DFSClient: Abandoning block blk_-1144491637577072681_1003
> 09/04/20 17:15:57 INFO dfs.DFSClient: Exception in createBlockOutputStream java.io.IOException:
> Bad connect ack with firstBadLink 192.168.0.66:50010
> 09/04/20 17:15:57 INFO dfs.DFSClient: Abandoning block blk_6574618270268421892_1003
> 09/04/20 17:16:03 WARN dfs.DFSClient: DataStreamer Exception: java.io.IOException:
> Unable to create new block.
> 	at org.apache.hadoop.dfs.DFSClient$DFSOutputStream.nextBlockOutputStream(DFSClient.java:2387)
> 	at org.apache.hadoop.dfs.DFSClient$DFSOutputStream.access$1800(DFSClient.java:1746)
> 	at org.apache.hadoop.dfs.DFSClient$DFSOutputStream$DataStreamer.run(DFSClient.java:1924)
> 09/04/20 17:16:03 WARN dfs.DFSClient: Error Recovery for block blk_6574618270268421892_1003
bad datanode[1]
> {noformat} 
> The tests were done with the following configuration:
> * Hadoop version 0.18.3
> * 3 data nodes with replication count of 2
> * 1 GB file write
> * 1 data node taken down during write
> This issue seems to be caused by the fact that there is a delay between the time a data
node goes down and the time it is marked as dead by the name node. This delay is unavoidable,
but the name node should not keep allocating new blocks to data nodes that are known to be
down by the client. Even by adjusting {{heartbeat.recheck.interval}}, there is still a window
during which this issue can occur.
> One possible fix would be to allow clients to exclude known bad data nodes when allocating
new blocks. See {{failed_write.patch}} for an example.

-- 
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