[
https://issues.apache.org/jira/browse/HADOOP-4379?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12710555#action_12710555
]
Hairong Kuang commented on HADOOP-4379:
---------------------------------------
If one of the datanodes in the pipeline has a very very slow disk, it is
possible that when sync returns, not all the syned data get flushed to the disk
yet. If this datanode dies and restarts before the lease recovery starts, I
think the lease recovery will remove the synced data.
> In HDFS, sync() not yet guarantees data available to the new readers
> --------------------------------------------------------------------
>
> Key: HADOOP-4379
> URL: https://issues.apache.org/jira/browse/HADOOP-4379
> Project: Hadoop Core
> Issue Type: New Feature
> Components: dfs
> Reporter: Tsz Wo (Nicholas), SZE
> Assignee: dhruba borthakur
> Priority: Blocker
> Fix For: 0.19.2
>
> Attachments: 4379_20081010TC3.java, fsyncConcurrentReaders.txt,
> fsyncConcurrentReaders3.patch, fsyncConcurrentReaders4.patch,
> fsyncConcurrentReaders5.txt, fsyncConcurrentReaders6.patch,
> fsyncConcurrentReaders9.patch, hypertable-namenode.log.gz, namenode.log,
> namenode.log, Reader.java, Reader.java, reopen_test.sh, ReopenProblem.java,
> Writer.java, Writer.java
>
>
> In the append design doc
> (https://issues.apache.org/jira/secure/attachment/12370562/Appends.doc), it
> says
> * A reader is guaranteed to be able to read data that was 'flushed' before
> the reader opened the file
> However, this feature is not yet implemented. Note that the operation
> 'flushed' is now called "sync".
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
