hadoop-hdfs-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Aaron T. Myers (Commented) (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HDFS-3067) NPE in DFSInputStream.readBuffer if read is repeated on corrupted block
Date Thu, 15 Mar 2012 05:13:38 GMT

    [ https://issues.apache.org/jira/browse/HDFS-3067?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13229898#comment-13229898
] 

Aaron T. Myers commented on HDFS-3067:
--------------------------------------

Just marking changing open/patch-available isn't sufficient to kick test-patch. You actually
need to upload a new patch. But, I've just kicked Jenkins for you manually. Build here: https://builds.apache.org/view/G-L/view/Hadoop/job/PreCommit-HDFS-Build/2008/
                
> NPE in DFSInputStream.readBuffer if read is repeated on corrupted block
> -----------------------------------------------------------------------
>
>                 Key: HDFS-3067
>                 URL: https://issues.apache.org/jira/browse/HDFS-3067
>             Project: Hadoop HDFS
>          Issue Type: Bug
>          Components: hdfs client
>    Affects Versions: 0.24.0
>            Reporter: Henry Robinson
>            Assignee: Henry Robinson
>         Attachments: HDFS-3067.1.patch, HDFS-3607.patch
>
>
> With a singly-replicated block that's corrupted, issuing a read against it twice in succession
(e.g. if ChecksumException is caught by the client) gives a NullPointerException.
> Here's the body of a test that reproduces the problem:
> {code}
>     final short REPL_FACTOR = 1;
>     final long FILE_LENGTH = 512L;
>     cluster.waitActive();
>     FileSystem fs = cluster.getFileSystem();
>     Path path = new Path("/corrupted");
>     DFSTestUtil.createFile(fs, path, FILE_LENGTH, REPL_FACTOR, 12345L);
>     DFSTestUtil.waitReplication(fs, path, REPL_FACTOR);
>     ExtendedBlock block = DFSTestUtil.getFirstBlock(fs, path);
>     int blockFilesCorrupted = cluster.corruptBlockOnDataNodes(block);
>     assertEquals("All replicas not corrupted", REPL_FACTOR, blockFilesCorrupted);
>     InetSocketAddress nnAddr =
>         new InetSocketAddress("localhost", cluster.getNameNodePort());
>     DFSClient client = new DFSClient(nnAddr, conf);
>     DFSInputStream dis = client.open(path.toString());
>     byte[] arr = new byte[(int)FILE_LENGTH];
>     boolean sawException = false;
>     try {
>       dis.read(arr, 0, (int)FILE_LENGTH);
>     } catch (ChecksumException ex) {     
>       sawException = true;
>     }
>     
>     assertTrue(sawException);
>     sawException = false;
>     try {
>       dis.read(arr, 0, (int)FILE_LENGTH); // <-- NPE thrown here
>     } catch (ChecksumException ex) {     
>       sawException = true;
>     } 
> {code}
> The stack:
> {code}
> java.lang.NullPointerException
> 	at org.apache.hadoop.hdfs.DFSInputStream.readBuffer(DFSInputStream.java:492)
> 	at org.apache.hadoop.hdfs.DFSInputStream.read(DFSInputStream.java:545)
>         [snip test stack]
> {code}
> and the problem is that currentNode is null. It's left at null after the first read,
which fails, and then is never refreshed because the condition in read that protects blockSeekTo
is only triggered if the current position is outside the block's range. 

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira

        

Mime
View raw message