[
https://issues.apache.org/jira/browse/FLUME-2905?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16058745#comment-16058745
]
Siddharth Ahuja commented on FLUME-2905:
----------------------------------------
Hi [~sati], thanks a lot for your review.
Please find my answers for your points:
* For point 1. - "calling stop() after writing out the exception", I have moved
stop() after logging the exception but just before it gets thrown.
* For point 2. - We should possibly have a dedicated JIRA for removing the
"return" statement from the stop() method as this would be a different issue to
what I am trying to fix in this JIRA which is to prevent socket leaks if a port
is already bound. Also, it would make tracking easier with a new JIRA as
otherwise any issues (if any) arising from this removal will be discussed in
this JIRA which is a side-track from the original issue that is already
potentially resolved. What do you think?
* For point 3 - I believe I have nothing to do here.
I have gone on and created a new patch - FLUME-2905-5.patch for your review.
I will try and add this to review board (haven't done that yet) soon.
Thanks once again.
> NetcatSource - Socket not closed when an exception is encountered during
> start() leading to file descriptor leaks
> -----------------------------------------------------------------------------------------------------------------
>
> Key: FLUME-2905
> URL: https://issues.apache.org/jira/browse/FLUME-2905
> Project: Flume
> Issue Type: Bug
> Components: Sinks+Sources
> Affects Versions: 1.6.0
> Reporter: Siddharth Ahuja
> Assignee: Siddharth Ahuja
> Attachments: FLUME-2905-0.patch, FLUME-2905-1.patch,
> FLUME-2905-2.patch, FLUME-2905-3.patch, FLUME-2905-4.patch
>
>
> During the flume agent start-up, the flume configuration containing the
> NetcatSource is parsed and the source's start() is called. If there is an
> issue while binding the channel's socket to a local address to configure the
> socket to listen for connections following exception is thrown but the socket
> open just before is not closed.
> {code}
> 2016-05-01 03:04:37,273 ERROR org.apache.flume.lifecycle.LifecycleSupervisor:
> Unable to start EventDrivenSourceRunner: {
> source:org.apache.flume.source.NetcatSource{name:src-1,state:IDLE} } -
> Exception follows.
> org.apache.flume.FlumeException: java.net.BindException: Address already in
> use
> at org.apache.flume.source.NetcatSource.start(NetcatSource.java:173)
> at
> org.apache.flume.source.EventDrivenSourceRunner.start(EventDrivenSourceRunner.java:44)
> at
> org.apache.flume.lifecycle.LifecycleSupervisor$MonitorRunnable.run(LifecycleSupervisor.java:251)
> at
> java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
> at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:304)
> at
> java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:178)
> at
> java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
> at
> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
> at
> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
> at java.lang.Thread.run(Thread.java:745)
> Caused by: java.net.BindException: Address already in use
> at sun.nio.ch.Net.bind0(Native Method)
> at sun.nio.ch.Net.bind(Net.java:444)
> at sun.nio.ch.Net.bind(Net.java:436)
> at
> sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:214)
> at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:74)
> at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:67)
> at org.apache.flume.source.NetcatSource.start(NetcatSource.java:167)
> ... 9 more
> {code}
> The source's start() is then called again leading to another socket being
> opened but not closed and so on. This leads to file descriptor (socket) leaks.
> This can be easily reproduced as follows:
> 1. Set Netcat as the source in flume agent configuration.
> 2. Set the bind port for the netcat source to a port which is already in use.
> e.g. in my case I used 50010 which is the port for DataNode's XCeiver
> Protocol in use by the HDFS service.
> 3. Start flume agent and perform "lsof -p <flume_process_id> | wc -l". Notice
> the file descriptors keep on growing due to socket leaks with errors like:
> "can't identify protocol".
--
This message was sent by Atlassian JIRA
(v6.4.14#64029)
