hadoop-hdfs-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "ramkrishna.s.vasudevan (JIRA)" <j...@apache.org>
Subject [jira] [Created] (HDFS-1982) Null pointer exception is thrown when NN restarts with a block lesser in size than the block that is present in DN1 but the generation stamp is greater in the NN
Date Mon, 23 May 2011 13:12:47 GMT
Null pointer exception is thrown when NN restarts with a block lesser in size than the block
that is present in DN1 but the generation stamp is greater in the NN 
------------------------------------------------------------------------------------------------------------------------------------------------------------------

                 Key: HDFS-1982
                 URL: https://issues.apache.org/jira/browse/HDFS-1982
             Project: Hadoop HDFS
          Issue Type: Bug
          Components: name-node
    Affects Versions: 0.20-append
         Environment: Linux
            Reporter: ramkrishna.s.vasudevan
             Fix For: 0.20-append


Conisder the following scenario. 
WE have a cluster with one NN and 2 DN.

We write some file.

One of the block is written in DN1 but not yet completed in DN2 local disk.

Now DN1 gets killed and so pipeline recovery happens for the block with the size as in DN2
but the generation stamp gets updated in the NN.

DN2 also gets killed.

Now restart NN and DN1
Now if NN restarts, the block that NN has greater time stamp but the size is lesser in the
NN.

This leads to Null pointer exception in addstoredblock api




--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira

Mime
View raw message