[ZOOKEEPER-1179] NettyServerCnxn does not properly close socket on 4 letter word requests

• Type: Bug
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 3.4.0
• Fix Version/s: 3.4.6, 3.5.0
• Component/s: server
• Release Note: Thanks Rakesh, you are right, this error is not happening anymore. Flavio, I'm closing this.
• Assignee: Rakesh Radhakrishnan
• Reporter: Camille Fournier
• Created: 13/Sep/11 16:20
• Updated: 13/Mar/14 18:17
• Resolved: 12/Feb/14 01:18

Description

When calling a 4-letter-word to a server configured to use NettyServerCnxnFactory, the factory will not properly cancel all the keys and close the socket after sending the response for the 4lw. The close request will throw this exception, and the thread will not shut down:
2011-09-13 12:14:17,546 - WARN [New I/O server worker #1-1:NettyServerCnxnFactory$CnxnChannelHandler@117] - Exception caught [id: 0x009300cc, /1.1.1.1:38542 => /139.172.114.138:2181] EXCEPTION: java.io.IOException: A non-blocking socket operation could not be completed immediately
java.io.IOException: A non-blocking socket operation could not be completed immediately
at sun.nio.ch.SocketDispatcher.close0(Native Method)
at sun.nio.ch.SocketDispatcher.preClose(SocketDispatcher.java:44)
at sun.nio.ch.SocketChannelImpl.implCloseSelectableChannel(SocketChannelImpl.java:684)
at java.nio.channels.spi.AbstractSelectableChannel.implCloseChannel(AbstractSelectableChannel.java:201)
at java.nio.channels.spi.AbstractInterruptibleChannel.close(AbstractInterruptibleChannel.java:97)
at org.jboss.netty.channel.socket.nio.NioWorker.close(NioWorker.java:593)
at org.jboss.netty.channel.socket.nio.NioServerSocketPipelineSink.handleAcceptedSocket(NioServerSocketPipelineSink.java:119)
at org.jboss.netty.channel.socket.nio.NioServerSocketPipelineSink.eventSunk(NioServerSocketPipelineSink.java:76)
at org.jboss.netty.channel.Channels.close(Channels.java:720)
at org.jboss.netty.channel.AbstractChannel.close(AbstractChannel.java:208)
at org.apache.zookeeper.server.NettyServerCnxn.close(NettyServerCnxn.java:116)
at org.apache.zookeeper.server.NettyServerCnxn.cleanupWriterSocket(NettyServerCnxn.java:241)
at org.apache.zookeeper.server.NettyServerCnxn.access$0(NettyServerCnxn.java:231)
at org.apache.zookeeper.server.NettyServerCnxn$CommandThread.run(NettyServerCnxn.java:314)
at org.apache.zookeeper.server.NettyServerCnxn$CommandThread.start(NettyServerCnxn.java:305)
at org.apache.zookeeper.server.NettyServerCnxn.checkFourLetterWord(NettyServerCnxn.java:674)
at org.apache.zookeeper.server.NettyServerCnxn.receiveMessage(NettyServerCnxn.java:791)
at org.apache.zookeeper.server.NettyServerCnxnFactory$CnxnChannelHandler.processMessage(NettyServerCnxnFactory.java:217)
at org.apache.zookeeper.server.NettyServerCnxnFactory$CnxnChannelHandler.messageReceived(NettyServerCnxnFactory.java:141)
at org.jboss.netty.channel.Channels.fireMessageReceived(Channels.java:274)
at org.jboss.netty.channel.Channels.fireMessageReceived(Channels.java:261)
at org.jboss.netty.channel.socket.nio.NioWorker.read(NioWorker.java:350)
at org.jboss.netty.channel.socket.nio.NioWorker.processSelectedKeys(NioWorker.java:281)
at org.jboss.netty.channel.socket.nio.NioWorker.run(NioWorker.java:201)
at org.jboss.netty.util.internal.IoWorkerRunnable.run(IoWorkerRunnable.java:46)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:619)

Issue Links

• is related to: ZOOKEEPER-1833 fix windows build
• is related to: ZOOKEEPER-1839 Deadlock in NettyServerCnxn