[ 
https://issues.apache.org/jira/browse/HDDS-2026?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Anu Engineer updated HDDS-2026:
-------------------------------
    Fix Version/s: 0.5.0
       Resolution: Fixed
           Status: Resolved  (was: Patch Available)

Thanks for the fixes. I have committed this to the trunk.

> Overlapping chunk region cannot be read concurrently
> ----------------------------------------------------
>
>                 Key: HDDS-2026
>                 URL: https://issues.apache.org/jira/browse/HDDS-2026
>             Project: Hadoop Distributed Data Store
>          Issue Type: Bug
>          Components: Ozone Datanode
>            Reporter: Doroszlai, Attila
>            Assignee: Doroszlai, Attila
>            Priority: Critical
>              Labels: pull-request-available
>             Fix For: 0.5.0
>
>         Attachments: HDDS-2026-repro.patch, changes.diff, 
> first-cut-proposed.diff
>
>          Time Spent: 2h
>  Remaining Estimate: 0h
>
> Concurrent requests to datanode for the same chunk may result in the 
> following exception in datanode:
> {code}
> java.nio.channels.OverlappingFileLockException
>    at java.base/sun.nio.ch.FileLockTable.checkList(FileLockTable.java:229)
>    at java.base/sun.nio.ch.FileLockTable.add(FileLockTable.java:123)
>    at 
> java.base/sun.nio.ch.AsynchronousFileChannelImpl.addToFileLockTable(AsynchronousFileChannelImpl.java:178)
>    at 
> java.base/sun.nio.ch.SimpleAsynchronousFileChannelImpl.implLock(SimpleAsynchronousFileChannelImpl.java:185)
>    at 
> java.base/sun.nio.ch.AsynchronousFileChannelImpl.lock(AsynchronousFileChannelImpl.java:118)
>    at 
> org.apache.hadoop.ozone.container.keyvalue.helpers.ChunkUtils.readData(ChunkUtils.java:175)
>    at 
> org.apache.hadoop.ozone.container.keyvalue.impl.ChunkManagerImpl.readChunk(ChunkManagerImpl.java:213)
>    at 
> org.apache.hadoop.ozone.container.keyvalue.KeyValueHandler.handleReadChunk(KeyValueHandler.java:574)
>    at 
> org.apache.hadoop.ozone.container.keyvalue.KeyValueHandler.handle(KeyValueHandler.java:195)
>    at 
> org.apache.hadoop.ozone.container.common.impl.HddsDispatcher.dispatchRequest(HddsDispatcher.java:271)
>    at 
> org.apache.hadoop.ozone.container.common.impl.HddsDispatcher.dispatch(HddsDispatcher.java:148)
>    at 
> org.apache.hadoop.ozone.container.common.transport.server.GrpcXceiverService$1.onNext(GrpcXceiverService.java:73)
>    at 
> org.apache.hadoop.ozone.container.common.transport.server.GrpcXceiverService$1.onNext(GrpcXceiverService.java:61)
> {code}
> It seems this is covered by retry logic, as key read is eventually successful 
> at client side.
> The problem is that:
> bq. File locks are held on behalf of the entire Java virtual machine. They 
> are not suitable for controlling access to a file by multiple threads within 
> the same virtual machine. 
> ([source|https://docs.oracle.com/javase/8/docs/api/java/nio/channels/FileLock.html])
> code ref: 
> [{{ChunkUtils.readData}}|https://github.com/apache/hadoop/blob/c92de8209d1c7da9e7ce607abeecb777c4a52c6a/hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/keyvalue/helpers/ChunkUtils.java#L175]



--
This message was sent by Atlassian Jira
(v8.3.2#803003)

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

Reply via email to