hadoop-hdfs-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Andrew Wang (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HDFS-12151) Hadoop 2 clients cannot writeBlock to Hadoop 3 DataNodes
Date Thu, 27 Jul 2017 17:57:00 GMT

    [ https://issues.apache.org/jira/browse/HDFS-12151?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16103610#comment-16103610
] 

Andrew Wang commented on HDFS-12151:
------------------------------------

Thanks Sean! Looks like the checkstyles could be fixed, and the new test failed with an NPE.
In the past, I've had issues with the thread-safety of mocking, which might be biting us here
too. Changing the catch to first separately catch RuntimeException and re-throw would give
us more detail on the NPE too.

Given Ewan's response, it sounds like it's worth cleaning up some other things in this code
too. I filed HDFS-12207 to track these separately, since they're less urgent than this change.

> Hadoop 2 clients cannot writeBlock to Hadoop 3 DataNodes
> --------------------------------------------------------
>
>                 Key: HDFS-12151
>                 URL: https://issues.apache.org/jira/browse/HDFS-12151
>             Project: Hadoop HDFS
>          Issue Type: Sub-task
>          Components: rolling upgrades
>    Affects Versions: 3.0.0-alpha4
>            Reporter: Sean Mackrory
>            Assignee: Sean Mackrory
>         Attachments: HDFS-12151.001.patch, HDFS-12151.002.patch
>
>
> Trying to write to a Hadoop 3 DataNode with a Hadoop 2 client currently fails. On the
client side it looks like this:
> {code}
>     17/07/14 13:31:58 INFO hdfs.DFSClient: Exception in createBlockOutputStream
>     java.io.EOFException: Premature EOF: no length prefix available
>             at org.apache.hadoop.hdfs.protocolPB.PBHelper.vintPrefixed(PBHelper.java:2280)
>             at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.createBlockOutputStream(DFSOutputStream.java:1318)
>             at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.nextBlockOutputStream(DFSOutputStream.java:1237)
>             at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.run(DFSOutputStream.java:449){code}
> But on the DataNode side there's an ArrayOutOfBoundsException because there aren't any
targetStorageIds:
> {code}
>     java.lang.ArrayIndexOutOfBoundsException: 0
>             at org.apache.hadoop.hdfs.server.datanode.DataXceiver.writeBlock(DataXceiver.java:815)
>             at org.apache.hadoop.hdfs.protocol.datatransfer.Receiver.opWriteBlock(Receiver.java:173)
>             at org.apache.hadoop.hdfs.protocol.datatransfer.Receiver.processOp(Receiver.java:107)
>             at org.apache.hadoop.hdfs.server.datanode.DataXceiver.run(DataXceiver.java:290)
>             at java.lang.Thread.run(Thread.java:745){code}



--
This message was sent by Atlassian JIRA
(v6.4.14#64029)

---------------------------------------------------------------------
To unsubscribe, e-mail: hdfs-issues-unsubscribe@hadoop.apache.org
For additional commands, e-mail: hdfs-issues-help@hadoop.apache.org


Mime
View raw message