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Posted to dev@zookeeper.apache.org by "Hugh Warrington (JIRA)" <ji...@apache.org> on 2011/01/27 17:45:44 UTC

[jira] Updated: (ZOOKEEPER-979) UnknownHostException in QuorumCnxManager

     [ https://issues.apache.org/jira/browse/ZOOKEEPER-979?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Hugh Warrington updated ZOOKEEPER-979:
--------------------------------------

    Description: 
I'm using zk 3.3.2 and I'm seeing this in my logs around startup:

2011-01-27 10:16:21,513 [WorkerSender Thread] WARN  org.apache.zookeeper.server.quorum.QuorumCnxManager - Cannot open channel to 0 at election address xxx.yyy.com/10.2.131.19:3888
java.net.UnknownHostException
	at sun.nio.ch.Net.translateException(Net.java:100)
	at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:140)
	at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:366)
	at org.apache.zookeeper.server.quorum.QuorumCnxManager.toSend(QuorumCnxManager.java:335)
	at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.process(FastLeaderElection.java:360)
	at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.run(FastLeaderElection.java:333)
	at java.lang.Thread.run(Thread.java:636)

And all subsequent zk ops give {{ConnectionLossException}}.

I've just explained this to breed_zk on IRC, and he asked me to file a ticket, mentioning that UnknownHostException may sometimes be thrown for reasons other than host resolution. While I'm reasonably certain that the hostname is correct and should be contactable, I need to put some more time into checking our network setup to be absolutely sure. However, two observations arose while looking into this:

* At the top of QuorumCnxManager.connectOne(), we set electionAddr (or fail and return). But then a few lines later we don't actually use this local variable in the call to connect(). This seems like a minor programming mistake (although AFAICT it doesn't change the behaviour).
* In the subsequent catch block, the UnknownHostException that's thrown doesn't contain the address that we were trying to connect to (though if you capture WARN log messages, you can see what it was).

  was:
I'm using zk 3.3.2 and I'm seeing this in my logs around startup:

{{2011-01-27 10:16:21,513 [WorkerSender Thread] WARN  org.apache.zookeeper.server.quorum.QuorumCnxManager - Cannot open channel to 0 at election address xxx.yyy.com/10.2.131.19:3888
java.net.UnknownHostException
	at sun.nio.ch.Net.translateException(Net.java:100)
	at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:140)
	at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:366)
	at org.apache.zookeeper.server.quorum.QuorumCnxManager.toSend(QuorumCnxManager.java:335)
	at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.process(FastLeaderElection.java:360)
	at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.run(FastLeaderElection.java:333)
	at java.lang.Thread.run(Thread.java:636)}}

And all subsequent zk ops give {{ConnectionLossException}}.

I've just explained this to breed_zk on IRC, and he asked me to file a ticket, mentioning that UnknownHostException may sometimes be thrown for reasons other than host resolution. While I'm reasonably certain that the hostname is correct and should be contactable, I need to put some more time into checking our network setup to be absolutely sure. However, two observations arose while looking into this:

* At the top of QuorumCnxManager.connectOne(), we set electionAddr (or fail and return). But then a few lines later we don't actually use this local variable in the call to connect(). This seems like a minor programming mistake (although AFAICT it doesn't change the behaviour).
* In the subsequent catch block, the UnknownHostException that's thrown doesn't contain the address that we were trying to connect to (though if you capture WARN log messages, you can see what it was).


> UnknownHostException in QuorumCnxManager
> ----------------------------------------
>
>                 Key: ZOOKEEPER-979
>                 URL: https://issues.apache.org/jira/browse/ZOOKEEPER-979
>             Project: ZooKeeper
>          Issue Type: Bug
>          Components: server
>    Affects Versions: 3.3.2
>            Reporter: Hugh Warrington
>            Priority: Minor
>
> I'm using zk 3.3.2 and I'm seeing this in my logs around startup:
> 2011-01-27 10:16:21,513 [WorkerSender Thread] WARN  org.apache.zookeeper.server.quorum.QuorumCnxManager - Cannot open channel to 0 at election address xxx.yyy.com/10.2.131.19:3888
> java.net.UnknownHostException
> 	at sun.nio.ch.Net.translateException(Net.java:100)
> 	at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:140)
> 	at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:366)
> 	at org.apache.zookeeper.server.quorum.QuorumCnxManager.toSend(QuorumCnxManager.java:335)
> 	at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.process(FastLeaderElection.java:360)
> 	at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.run(FastLeaderElection.java:333)
> 	at java.lang.Thread.run(Thread.java:636)
> And all subsequent zk ops give {{ConnectionLossException}}.
> I've just explained this to breed_zk on IRC, and he asked me to file a ticket, mentioning that UnknownHostException may sometimes be thrown for reasons other than host resolution. While I'm reasonably certain that the hostname is correct and should be contactable, I need to put some more time into checking our network setup to be absolutely sure. However, two observations arose while looking into this:
> * At the top of QuorumCnxManager.connectOne(), we set electionAddr (or fail and return). But then a few lines later we don't actually use this local variable in the call to connect(). This seems like a minor programming mistake (although AFAICT it doesn't change the behaviour).
> * In the subsequent catch block, the UnknownHostException that's thrown doesn't contain the address that we were trying to connect to (though if you capture WARN log messages, you can see what it was).

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