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https://issues.apache.org/jira/browse/HDFS-1542?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Todd Lipcon updated HDFS-1542:
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Attachment: hdfs-1542.txt
Here's one possible fix.
It's very slightly incompatible in that it used to be that we could make a
FileSystem using a Configuration, then change settings in that Configuration
(_after_ the FS was created) and they'd be reflected in open streams. This was
only true for _some_ of the configurations, so I think it was probably more of
a bug than a feature.
What do you think? I think fixing it at this layer makes more sense than
changing Configuration.writeXML to copy itself first.
> Deadlock in Configuration.writeXml when serialized form is larger than one
> DFS block
> ------------------------------------------------------------------------------------
>
> Key: HDFS-1542
> URL: https://issues.apache.org/jira/browse/HDFS-1542
> Project: Hadoop HDFS
> Issue Type: Bug
> Components: hdfs client
> Affects Versions: 0.22.0, 0.23.0
> Reporter: Todd Lipcon
> Priority: Critical
> Attachments: deadlock.txt, hdfs-1542.txt, Test.java
>
>
> Configuration.writeXml holds a lock on itself and then writes the XML to an
> output stream, during which DFSOutputStream will try to get a lock on
> ackQueue/dataQueue. Meanwihle the DataStreamer thread will call functions
> like conf.getInt() and deadlock against the other thread, since it could be
> the same conf object.
> This causes a deterministic deadlock whenever the serialized form is larger
> than block size.
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