Hi,
We are having issues with our web interface (WI) to zookeeper. We
deployed a java app (WI), in tomcat, which shows a (mostly read-only) UI for
the zk tree, in our cluster. The app had been deployed quite some time ago.
However, recently, it is going down many times, in the recent past, showing
these errors in the catalina.out. These errors are coming continuously in the
catalina.out, while the website is down.
<catalina.out>
[INFO] SyncZKTreeWatcher - [registerWatches] About to register watch for
'/llf/version-1.0/serverNodes/llf-server/nodes/b3091258:8085/connected',
recursive: false
[INFO] SyncZKTreeWatcher - Path: null, type: None, state: Disconnected
[INFO] SyncZKTreeWatcher - Path: null, type: None, state: SyncConnected
[WARN] SyncZKTreeWatcher - [run] Exception while handling event WatchedEvent:
Znode change. Path:
/llf/version-1.0/serverNodes/llf-server/nodes/b3091258:8085/connected Type:
NodeChildrenChanged
<org.apache.zookeeper.KeeperException$ConnectionLossException: KeeperErrorCode
= ConnectionLoss>org.apache.zookeeper.KeeperException$ConnectionLossException:
KeeperErrorCode = ConnectionLoss
at org.apache.zookeeper.KeeperException.create(KeeperException.java:90)
at org.apache.zookeeper.ZooKeeper.getData(ZooKeeper.java:809)
at org.apache.zookeeper.ZooKeeper.getData(ZooKeeper.java:837)
at
com.yahoo.cluster.zookeeper.SyncZKTreeWatcher.getNodeValue(SyncZKTreeWatcher.java:465)
at
com.yahoo.cluster.zookeeper.SyncZKTreeWatcher.registerWatches(SyncZKTreeWatcher.java:376)
at
com.yahoo.cluster.zookeeper.SyncZKTreeWatcher.access$100(SyncZKTreeWatcher.java:37)
at
com.yahoo.cluster.zookeeper.SyncZKTreeWatcher$1.run(SyncZKTreeWatcher.java:169)
at java.lang.Thread.run(Thread.java:619)
</catalina.out>
In another log, we are getting the following errors continuously.
<AlertReceiver.log>
java.net.SocketException: Transport endpoint is not connected
at sun.nio.ch.SocketChannelImpl.shutdown(Native Method)
at
sun.nio.ch.SocketChannelImpl.shutdownOutput(SocketChannelImpl.java:651)
at sun.nio.ch.SocketAdaptor.shutdownOutput(SocketAdaptor.java:368)
at
org.apache.zookeeper.ClientCnxn$SendThread.cleanup(ClientCnxn.java:935)
at org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:901)
2010 03 16 09:49:55,645 org.apache.zookeeper.ClientCnxn ZK Event
Handler-SendThread Attempting connection to server
b3091279.crawl.yahoo.net/67.195.112.40:22801
2010 03 16 09:49:55,646 org.apache.zookeeper.ClientCnxn ZK Event
Handler-SendThread Priming connection to
java.nio.channels.SocketChannel[connected local=/67.195.37.119:38793
remote=b3091279.crawl.yahoo.net/67.195.112.40:22801]
2010 03 16 09:49:55,739 org.apache.zookeeper.ClientCnxn ZK Event
Handler-SendThread Server connection successful
2010 03 16 09:49:55,775 org.apache.zookeeper.ClientCnxn ZK Event
Handler-SendThread Exception closing session 0xe727001201aa32ab to
sun.nio.ch.selectionkeyi...@3ef92f5e<mailto:sun.nio.ch.selectionkeyi...@3ef92f5e>
java.io.IOException: Read error rc = -1 java.nio.DirectByteBuffer[pos=0 lim=4
cap=4]
at org.apache.zookeeper.ClientCnxn$SendThread.doIO(ClientCnxn.java:632)
at org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:876)
2010 03 16 09:49:55,775 org.apache.zookeeper.ClientCnxn ZK Event
Handler-SendThread Ignoring exception during shutdown input
</AlertReceiver.log>
What do these errors indicate? Always, restarting tomcat helps. But
since the problem is occurring many times, we want to understand why is this
happening? Is there a known ZK issue which could cause such behavior?
Thanks
Udaya
