hadoop-common-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "dhruba borthakur (JIRA)" <j...@apache.org>
Subject [jira] Commented: (HADOOP-4379) In HDFS, sync() not yet guarantees data available to the new readers
Date Wed, 04 Feb 2009 09:49:59 GMT

    [ https://issues.apache.org/jira/browse/HADOOP-4379?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12670292#action_12670292
] 

dhruba borthakur commented on HADOOP-4379:
------------------------------------------

Hi Doug,

ReopenProblem.java is guaranteed to hang. At line 189, you create an file and get an handle
on this file. Then , at line 197, you use the *same* file system object and invoke waitForLeaseRecovery().
waitForLeaseRecovery tries to open the same file again for appending to it. It fails as expected.
 The namenode log correctly shows that the "same leaseholder is trying to reopen the file
for appends"!

does it make sense? Thanks, dhruba

> 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: 0.19.1
>
>         Attachments: 4379_20081010TC3.java, fsyncConcurrentReaders.txt, fsyncConcurrentReaders3.patch,
fsyncConcurrentReaders4.patch, hypertable-namenode.log.gz, 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.


Mime
View raw message