[ 
https://issues.apache.org/jira/browse/HADOOP-4681?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12649789#action_12649789
 ] 

Hadoop QA commented on HADOOP-4681:
-----------------------------------

-1 overall.  Here are the results of testing the latest attachment 
  http://issues.apache.org/jira/secure/attachment/12394193/4681.patch
  against trunk revision 719431.

    +1 @author.  The patch does not contain any @author tags.

    -1 tests included.  The patch doesn't appear to include any new or modified 
tests.
                        Please justify why no tests are needed for this patch.

    +1 javadoc.  The javadoc tool did not generate any warning messages.

    +1 javac.  The applied patch does not increase the total number of javac 
compiler warnings.

    +1 findbugs.  The patch does not introduce any new Findbugs warnings.

    +1 Eclipse classpath. The patch retains Eclipse classpath integrity.

    -1 core tests.  The patch failed core unit tests.

    +1 contrib tests.  The patch passed contrib unit tests.

Test results: 
http://hudson.zones.apache.org/hudson/job/Hadoop-Patch/3621/testReport/
Findbugs warnings: 
http://hudson.zones.apache.org/hudson/job/Hadoop-Patch/3621/artifact/trunk/build/test/findbugs/newPatchFindbugsWarnings.html
Checkstyle results: 
http://hudson.zones.apache.org/hudson/job/Hadoop-Patch/3621/artifact/trunk/build/test/checkstyle-errors.html
Console output: 
http://hudson.zones.apache.org/hudson/job/Hadoop-Patch/3621/console

This message is automatically generated.

> DFSClient block read failures cause open DFSInputStream to become unusable
> --------------------------------------------------------------------------
>
>                 Key: HADOOP-4681
>                 URL: https://issues.apache.org/jira/browse/HADOOP-4681
>             Project: Hadoop Core
>          Issue Type: Bug
>    Affects Versions: 0.18.2, 0.19.0, 0.19.1, 0.20.0
>            Reporter: Igor Bolotin
>             Fix For: 0.19.1, 0.20.0
>
>         Attachments: 4681.patch
>
>
> We are using some Lucene indexes directly from HDFS and for quite long time 
> we were using Hadoop version 0.15.3.
> When tried to upgrade to Hadoop 0.19 - index searches started to fail with 
> exceptions like:
> 2008-11-13 16:50:20,314 WARN [Listener-4] [] DFSClient : DFS Read: 
> java.io.IOException: Could not obtain block: blk_5604690829708125511_15489 
> file=/usr/collarity/data/urls-new/part-00000/20081110-163426/_0.tis
> at 
> org.apache.hadoop.hdfs.DFSClient$DFSInputStream.chooseDataNode(DFSClient.java:1708)
> at 
> org.apache.hadoop.hdfs.DFSClient$DFSInputStream.blockSeekTo(DFSClient.java:1536)
> at org.apache.hadoop.hdfs.DFSClient$DFSInputStream.read(DFSClient.java:1663)
> at java.io.DataInputStream.read(DataInputStream.java:132)
> at 
> org.apache.nutch.indexer.FsDirectory$DfsIndexInput.readInternal(FsDirectory.java:174)
> at 
> org.apache.lucene.store.BufferedIndexInput.refill(BufferedIndexInput.java:152)
> at 
> org.apache.lucene.store.BufferedIndexInput.readByte(BufferedIndexInput.java:38)
> at org.apache.lucene.store.IndexInput.readVInt(IndexInput.java:76)
> at org.apache.lucene.index.TermBuffer.read(TermBuffer.java:63)
> at org.apache.lucene.index.SegmentTermEnum.next(SegmentTermEnum.java:131)
> at org.apache.lucene.index.SegmentTermEnum.scanTo(SegmentTermEnum.java:162)
> at org.apache.lucene.index.TermInfosReader.scanEnum(TermInfosReader.java:223)
> at org.apache.lucene.index.TermInfosReader.get(TermInfosReader.java:217)
> at org.apache.lucene.index.SegmentTermDocs.seek(SegmentTermDocs.java:54) 
> ...
> The investigation showed that the root of this issue is that we exceeded # of 
> xcievers in the data nodes and that was fixed by changing configuration 
> settings to 2k.
> However - one thing that bothered me was that even after datanodes recovered 
> from overload and most of client servers had been shut down - we still 
> observed errors in the logs of running servers.
> Further investigation showed that fix for HADOOP-1911 introduced another 
> problem - the DFSInputStream instance might become unusable once number of 
> failures over lifetime of this instance exceeds configured threshold.
> The fix for this specific issue seems to be trivial - just reset failure 
> counter before reading next block (patch will be attached shortly).
> This seems to be also related to HADOOP-3185, but I'm not sure I really 
> understand necessity of keeping track of failed block accesses in the DFS 
> client.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.

Reply via email to