[ 
https://issues.apache.org/jira/browse/HADOOP-820?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_12537164
 ] 

Konstantin Shvachko commented on HADOOP-820:
--------------------------------------------

You cannot rely on file mod times. It is not supported by all file systems, and 
time is not expected to be synchronized across different 
(mounted) file systems. That is why the name-node creates a special file 
fstime, which contains latest mod time for the image generated
centrally on the name-node once and the same for all image directories.
This issue is very distantly related to the issue you describe imo.

> NameNode startup fails if edit log terminates prematurely
> ---------------------------------------------------------
>
>                 Key: HADOOP-820
>                 URL: https://issues.apache.org/jira/browse/HADOOP-820
>             Project: Hadoop
>          Issue Type: Bug
>          Components: dfs
>         Environment: ~50 node cluster
>            Reporter: Bryan Pendleton
>            Assignee: Raghu Angadi
>         Attachments: fixNameNodeStartup.patch
>
>
> I ran out of space on the device that stores the edit log, resulting in an 
> edit log that is truncated mid transaction.
> Ideally, the NameNode should start up, in SafeMode or the like, whenever this 
> happens. Right now, you get this stack trace:
> 2006-12-12 15:33:57,212 ERROR org.apache.hadoop.dfs.NameNode: 
> java.io.EOFExcepti
> on
>         at java.io.DataInputStream.readUnsignedShort(DataInputStream.java:310)
>         at org.apache.hadoop.io.UTF8.readFields(UTF8.java:104)
>         at org.apache.hadoop.dfs.FSEditLog.loadFSEdits(FSEditLog.java:227)
>         at org.apache.hadoop.dfs.FSImage.loadFSImage(FSImage.java:191)
>         at org.apache.hadoop.dfs.FSDirectory.loadFSImage(FSDirectory.java:320)
>         at org.apache.hadoop.dfs.FSNamesystem.<init>(FSNamesystem.java:226)
>         at org.apache.hadoop.dfs.NameNode.<init>(NameNode.java:146)
>         at org.apache.hadoop.dfs.NameNode.<init>(NameNode.java:138)
>         at org.apache.hadoop.dfs.NameNode.main(NameNode.java:589)

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

Reply via email to