[
https://issues.apache.org/jira/browse/HADOOP-4379?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12677135#action_12677135
]
Jim Kellerman commented on HADOOP-4379:
---------------------------------------
> dhruba borthakur - 26/Feb/09 11:35 AM
> @Jim: Were u using ReopenProblem.java:waitForLeaseRecovery() and still seeing
> that it takes upto an hour for the
> waitForLeaseRecovery() method to return success?
Well, sort of. my code is similar but inline in the module that uses it:
{code}
// Recover the files lease if necessary
boolean recovered = false;
while (!recovered) {
try {
FSDataOutputStream out = fs.append(logfiles[i].getPath());
out.close();
recovered = true;
} catch (IOException e) {
if (LOG.isDebugEnabled()) {
LOG.debug("Triggering lease recovery.");
}
try {
Thread.sleep(leaseRecoveryPeriod);
} catch (InterruptedException ex) {
// ignore it and try again
}
}
}
{code}
> This can happen if the original client that was writing to the file was alive
> and was in communication with the namenode.
> In this case, the new append-er will not be able to recover the original
> lease.
This was definitely not the case. The original writing process was kill'ed -9
Like Hypertable, HBase has a mechanism to detect when the original writing
process is dead.
> 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, 0.20.0
>
> 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.
