[
https://issues.apache.org/jira/browse/HDFS-1779?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13014041#comment-13014041
]
Uma Maheswara Rao G commented on HDFS-1779:
-------------------------------------------
Thanks to Druba and Todd for spending time and giving comments.
Datanodes already sends their blockRecieved command to NN successfull blocks.
After this, NN restart happend then this problem problem can come. Because
DataNode will not send any information about bbw.So NN can not find this
partial blcok presents in which node.
My proposal would be , When namenode is restarted, the datanode will
re-register with the namenode. During datanode registration, can we recover the
blocks in blocksBeingWritten directory ( sending bbw details to NN)? I
verified this with two DNs, it works for normal scenarios. Do you think any
impact with this ?
> After NameNode restart , Clients can not read partial files even after client
> invokes Sync.
> -------------------------------------------------------------------------------------------
>
> Key: HDFS-1779
> URL: https://issues.apache.org/jira/browse/HDFS-1779
> Project: Hadoop HDFS
> Issue Type: Bug
> Components: data-node, name-node
> Affects Versions: 0.20-append
> Environment: Linux
> Reporter: Uma Maheswara Rao G
> Assignee: Uma Maheswara Rao G
>
> In Append HDFS-200 issue,
> If file has 10 blocks and after writing 5 blocks if client invokes sync
> method then NN will persist the blocks information in edits.
> After this if we restart the NN, All the DataNodes will reregister with NN.
> But DataNodes are not sending the blocks being written information to NN. DNs
> are sending the blocksBeingWritten information in DN startup. So, here
> NameNode can not find that the 5 persisted blocks belongs to which datanodes.
> This information can build based on block reports from DN. Otherwise we will
> loose this 5 blocks information even NN persisted that block information in
> edits.
--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira
