我有一个简单的mvc应用程序，它存储com.datastax.driver.core.Session类的单个实例。此应用程序连接到10个节点的集群。其中6个是Cassandra节点，2个Hadoop节点和2个Solar节点。当它们被添加到查询主机列表中时，我可以看到节点的所有IP地址。
一切正常但是当我让应用程序运行一段时间而不使用时，我得到以下内容：
2013-12-18 14:07:53,589 [New I/O worker #6] DEBUG [ c.d.d.c.Connection] - Defuncting connection to /10.201.39.25
com.datastax.driver.core.TransportException: [/10.201.39.25] Unexpected exception triggered (java.io.IOException: An existing connection was forcibly closed by the remote host)
at com.datastax.driver.core.Connection$Dispatcher.exceptionCaught(Connection.java:581) [cassandra-driver-core-1.0.4-dse.jar:na]
at org.jboss.netty.channel.SimpleChannelUpstreamHandler.handleUpstream(SimpleChannelUpstreamHandler.java:112) [netty-3.7.0.Final.jar:na]
at org.jboss.netty.channel.DefaultChannelPipeline.sendUpstream(DefaultChannelPipeline.java:564) [netty-3.7.0.Final.jar:na]
at org.jboss.netty.channel.DefaultChannelPipeline$DefaultChannelHandlerContext.sendUpstream(DefaultChannelPipeline.java:791) [netty-3.7.0.Final.jar:na]
at org.jboss.netty.handler.codec.oneone.OneToOneDecoder.handleUpstream(OneToOneDecoder.java:60) [netty-3.7.0.Final.jar:na]
at org.jboss.netty.channel.DefaultChannelPipeline.sendUpstream(DefaultChannelPipeline.java:564) [netty-3.7.0.Final.jar:na]
at org.jboss.netty.channel.DefaultChannelPipeline$DefaultChannelHandlerContext.sendUpstream(DefaultChannelPipeline.java:791) [netty-3.7.0.Final.jar:na]
at org.jboss.netty.handler.codec.oneone.OneToOneDecoder.handleUpstream(OneToOneDecoder.java:60) [netty-3.7.0.Final.jar:na]
at org.jboss.netty.channel.DefaultChannelPipeline.sendUpstream(DefaultChannelPipeline.java:564) [netty-3.7.0.Final.jar:na]
at org.jboss.netty.channel.DefaultChannelPipeline$DefaultChannelHandlerContext.sendUpstream(DefaultChannelPipeline.java:791) [netty-3.7.0.Final.jar:na]
at org.jboss.netty.handler.codec.frame.FrameDecoder.exceptionCaught(FrameDecoder.java:377) [netty-3.7.0.Final.jar:na]
at org.jboss.netty.channel.SimpleChannelUpstreamHandler.handleUpstream(SimpleChannelUpstreamHandler.java:112) [netty-3.7.0.Final.jar:na]
at org.jboss.netty.channel.DefaultChannelPipeline.sendUpstream(DefaultChannelPipeline.java:564) [netty-3.7.0.Final.jar:na]
at org.jboss.netty.channel.DefaultChannelPipeline.sendUpstream(DefaultChannelPipeline.java:559) [netty-3.7.0.Final.jar:na]
at org.jboss.netty.channel.Channels.fireExceptionCaught(Channels.java:525) [netty-3.7.0.Final.jar:na]
at org.jboss.netty.channel.socket.nio.NioWorker.read(NioWorker.java:74) [netty-3.7.0.Final.jar:na]
at org.jboss.netty.channel.socket.nio.AbstractNioWorker.process(AbstractNioWorker.java:109) [netty-3.7.0.Final.jar:na]
at org.jboss.netty.channel.socket.nio.AbstractNioSelector.run(AbstractNioSelector.java:312) [netty-3.7.0.Final.jar:na]
at org.jboss.netty.channel.socket.nio.AbstractNioWorker.run(AbstractNioWorker.java:90) [netty-3.7.0.Final.jar:na]
at org.jboss.netty.channel.socket.nio.NioWorker.run(NioWorker.java:178) [netty-3.7.0.Final.jar:na]
at org.jboss.netty.util.ThreadRenamingRunnable.run(ThreadRenamingRunnable.java:108) [netty-3.7.0.Final.jar:na]
at org.jboss.netty.util.internal.DeadLockProofWorker$1.run(DeadLockProofWorker.java:42) [netty-3.7.0.Final.jar:na]
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) [na:1.6.0_25-ea]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) [na:1.6.0_25-ea]
at java.lang.Thread.run(Thread.java:662) [na:1.6.0_25-ea]
Caused by: java.io.IOException: An existing connection was forcibly closed by the remote host
at sun.nio.ch.SocketDispatcher.read0(Native Method) ~[na:1.6.0_25-ea]
at sun.nio.ch.SocketDispatcher.read(SocketDispatcher.java:25) ~[na:1.6.0_25-ea]
at sun.nio.ch.IOUtil.readIntoNativeBuffer(IOUtil.java:202) ~[na:1.6.0_25-ea]
at sun.nio.ch.IOUtil.read(IOUtil.java:169) ~[na:1.6.0_25-ea]
at sun.nio.ch.SocketChannelImpl.read(SocketChannelImpl.java:243) ~[na:1.6.0_25-ea]
at org.jboss.netty.channel.socket.nio.NioWorker.read(NioWorker.java:64) [netty-3.7.0.Final.jar:na]
at org.jboss.netty.channel.socket.nio.AbstractNioWorker.process(AbstractNioWorker.java:109) [netty-3.7.0.Final.jar:na]
at org.jboss.netty.channel.socket.nio.AbstractNioSelector.run(AbstractNioSelector.java:312) [netty-3.7.0.Final.jar:na]
at org.jboss.netty.channel.socket.nio.AbstractNioWorker.run(AbstractNioWorker.java:90) [netty-3.7.0.Final.jar:na]
at org.jboss.netty.channel.socket.nio.NioWorker.run(NioWorker.java:178) [netty-3.7.0.Final.jar:na]
... 3 common frames omitted
2013-12-18 14:07:53,698 [New I/O worker #6] DEBUG [ c.d.d.c.Cluster] - /10.201.39.25 is down, scheduling connection retries
2013-12-18 14:07:53,729 [Cassandra Java Driver worker-2] DEBUG [ c.d.d.c.HostConnectionPool] - Shutting down pool
2013-12-18 14:07:53,823 [New I/O worker #6] DEBUG [ c.d.d.c.AbstractReconnectionHandler] - First reconnection scheduled in 1000ms
2013-12-18 14:07:53,901 [New I/O worker #6] DEBUG [ c.d.d.c.RequestHandler] - Error querying /10.201.39.25, trying next host (error is: [/10.201.39.25] Unexpected exception triggered (java.io.IOException: An existing connection was forcibly closed by the remote host))
以上重复所有节点。毕竟我得到了：
SEVERE: Servlet.service() for servlet [appServlet] in context with path [/logging] threw exception [Request processing failed; nested exception is com.datastax.driver.core.exceptions.NoHostAvailableException: All host(s) tried for query failed (tried: [/10.201.39.26, /10.201.39.25, /10.201.39.15, /10.201.39.19, /10.201.39.16, /10.201.39.17, /10.201.39.22, /10.201.39.21] - use getErrors() for details)] with root cause
com.datastax.driver.core.exceptions.NoHostAvailableException: All host(s) tried for query failed (tried: [/10.201.39.26, /10.201.39.25, /10.201.39.15, /10.201.39.19, /10.201.39.16, /10.201.39.17, /10.201.39.22, /10.201.39.21] - use getErrors() for details)
at com.datastax.driver.core.RequestHandler.sendRequest(RequestHandler.java:102)
at com.datastax.driver.core.RequestHandler$1.run(RequestHandler.java:173)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:662)
2013-12-18 14:07:54,620 [Cassandra Java Driver worker-5] DEBUG [ c.d.d.c.ControlConnection] - [Control connection] Refreshing node list and token map
2013-12-18 14:07:54,885 [Reconnection-1] DEBUG [ c.d.d.c.Cluster] - Successful reconnection to /10.201.39.25, setting host UP
2013-12-18 14:07:54,885 [Reconnection-1] DEBUG [ c.d.d.c.Cluster] - Cancelling reconnection attempt since node is UP
2013-12-18 14:07:54,885 [Cassandra Java Driver worker-10] DEBUG [ c.d.d.c.Session] - Adding /10.201.39.25 to list of queried hosts
2013-12-18 14:07:54,948 [Cassandra Java Driver worker-5] DEBUG [ c.d.d.c.ControlConnection] - [Control connection] Refreshing schema
2013-12-18 14:07:55,213 [Reconnection-0] DEBUG [ c.d.d.c.Cluster] - Successful reconnection to /10.201.39.15, setting host UP
2013-12-18 14:07:55,213 [Reconnection-0] DEBUG [ c.d.d.c.Cluster] - Cancelling reconnection attempt since node is UP
2013-12-18 14:07:55,213 [Cassandra Java Driver worker-10] DEBUG [ c.d.d.c.Session] - Adding /10.201.39.15 to list of queried hosts
2013-12-18 14:07:55,463 [Reconnection-1] DEBUG [ c.d.d.c.Cluster] - Successful reconnection to /10.201.39.26, setting host UP
2013-12-18 14:07:55,463 [Reconnection-1] DEBUG [ c.d.d.c.Cluster] - Cancelling reconnection attempt since node is UP
2013-12-18 14:07:55,463 [Cassandra Java Driver worker-10] DEBUG [ c.d.d.c.Session] - Adding /10.201.39.26 to list of queried hosts
2013-12-18 14:07:55,463 [Reconnection-1] DEBUG [ c.d.d.c.Cluster] - Successful reconnection to /10.201.39.19, setting host UP
2013-12-18 14:07:55,463 [Reconnection-1] DEBUG [ c.d.d.c.Cluster] - Cancelling reconnection attempt since node is UP
2013-12-18 14:07:55,463 [Cassandra Java Driver worker-9] DEBUG [ c.d.d.c.Session] - Adding /10.201.39.19 to list of queried hosts
2013-12-18 14:07:55,463 [Reconnection-0] DEBUG [ c.d.d.c.Cluster] - Successful reconnection to /10.201.39.16, setting host UP
2013-12-18 14:07:55,463 [Reconnection-0] DEBUG [ c.d.d.c.Cluster] - Cancelling reconnection attempt since node is UP
2013-12-18 14:07:55,463 [Cassandra Java Driver worker-6] DEBUG [ c.d.d.c.Session] - Adding /10.201.39.16 to list of queried hosts
2013-12-18 14:07:55,494 [Reconnection-0] DEBUG [ c.d.d.c.Cluster] - Successful reconnection to /10.201.39.18, setting host UP
2013-12-18 14:07:55,494 [Reconnection-1] DEBUG [ c.d.d.c.Cluster] - Successful reconnection to /10.201.39.20, setting host UP
2013-12-18 14:07:55,494 [Reconnection-0] DEBUG [ c.d.d.c.Cluster] - Cancelling reconnection attempt since node is UP
2013-12-18 14:07:55,494 [Reconnection-1] DEBUG [ c.d.d.c.Cluster] - Cancelling reconnection attempt since node is UP
2013-12-18 14:07:55,494 [Cassandra Java Driver worker-10] DEBUG [ c.d.d.c.Session] - Adding /10.201.39.18 to list of queried hosts
2013-12-18 14:07:55,494 [Cassandra Java Driver worker-3] DEBUG [ c.d.d.c.Session] - Adding /10.201.39.20 to list of queried hosts
2013-12-18 14:07:55,666 [Cassandra Java Driver worker-5] DEBUG [ c.d.d.c.ControlConnection] - [Control connection] Successfully connected to /10.201.39.21
2013-12-18 14:08:03,728 [Hashed wheel timer #1] DEBUG [ c.d.d.c.Cluster] - /10.201.39.18 is down, scheduling connection retries
2013-12-18 14:08:03,728 [Cassandra Java Driver worker-5] DEBUG [ c.d.d.c.HostConnectionPool] - Shutting down pool
2013-12-18 14:08:03,728 [Hashed wheel timer #1] DEBUG [ c.d.d.c.AbstractReconnectionHandler] - First reconnection scheduled in 1000ms
2013-12-18 14:08:03,728 [Hashed wheel timer #1] DEBUG [ c.d.d.c.RequestHandler] - Error querying /10.201.39.25, trying next host (error is: Timeout during read)
2013-12-18 14:08:04,774 [Reconnection-1] DEBUG [ c.d.d.c.Cluster] - Successful reconnection to /10.201.39.18, setting host UP
2013-12-18 14:08:04,774 [Reconnection-1] DEBUG [ c.d.d.c.Cluster] - Cancelling reconnection attempt since node is UP
2013-12-18 14:08:04,774 [Cassandra Java Driver worker-3] DEBUG [ c.d.d.c.Session] - Adding /10.201.39.18 to list of queried hosts
2013-12-18 14:08:05,930 [Hashed wheel timer #1] DEBUG [ c.d.d.c.Cluster] - /10.201.39.18 is down, scheduling connection retries
2013-12-18 14:08:05,930 [Cassandra Java Driver worker-3] DEBUG [ c.d.d.c.HostConnectionPool] - Shutting down pool
2013-12-18 14:08:05,930 [Hashed wheel timer #1] DEBUG [ c.d.d.c.AbstractReconnectionHandler] - First reconnection scheduled in 1000ms
2013-12-18 14:08:05,930 [Hashed wheel timer #1] DEBUG [ c.d.d.c.RequestHandler] - Error querying /10.201.39.16, trying next host (error is: Timeout during read)
2013-12-18 14:08:06,040 [Hashed wheel timer #1] DEBUG [ c.d.d.c.RequestHandler] - Error querying /10.201.39.15, trying next host (error is: Timeout during read)
2013-12-18 14:08:06,134 [Hashed wheel timer #1] DEBUG [ c.d.d.c.RequestHandler] - Error querying /10.201.39.20, trying next host (error is: Timeout during read)
2013-12-18 14:08:06,134 [Hashed wheel timer #1] DEBUG [ c.d.d.c.RequestHandler] - Error querying /10.201.39.21, trying next host (error is: Timeout during read)
2013-12-18 14:08:06,134 [Hashed wheel timer #1] DEBUG [ c.d.d.c.RequestHandler] - Error querying /10.201.39.26, trying next host (error is: Timeout during read)
2013-12-18 14:08:06,134 [Hashed wheel timer #1] DEBUG [ c.d.d.c.RequestHandler] - Error querying /10.201.39.17, trying next host (error is: Timeout during read)
2013-12-18 14:08:06,134 [Hashed wheel timer #1] DEBUG [ c.d.d.c.RequestHandler] - Error querying /10.201.39.19, trying next host (error is: Timeout during read)
2013-12-18 14:08:06,134 [Hashed wheel timer #1] DEBUG [ c.d.d.c.RequestHandler] - Error querying /10.201.39.22, trying next host (error is: Timeout during read)
2013-12-18 14:08:06,227 [Hashed wheel timer #1] DEBUG [ c.d.d.c.RequestHandler] - Error querying /10.201.39.18, trying next host (error is: Timeout during read)
2013-12-18 14:08:06,946 [Reconnection-0] DEBUG [ c.d.d.c.Cluster] - Successful reconnection to /10.201.39.18, setting host UP
2013-12-18 14:08:06,946 [Reconnection-0] DEBUG [ c.d.d.c.Cluster] - Cancelling reconnection attempt since node is UP
2013-12-18 14:08:06,946 [Cassandra Java Driver worker-6] DEBUG [ c.d.d.c.Session] - Adding /10.201.39.18 to list of queried hosts
然后它似乎在此之后自行解决。
要创建会话对象，我使用了代码：
String[] hostsArray = hosts.split(",");
Cluster cluster = Cluster.builder().addContactPoints(hostsArray).withPort(port).build();
session = cluster.connect(keyspace);
会话对象存储为类的成员。在cassandra节点上，我在大约相同的时间段内在日志中看不到任何异常。在我的群集和会话对象的设置中是否存在我缺少的东西？我应该添加更多配置吗？
我应该补充一点，我从Windows机器上运行客户端应用程序。当我将客户端应用程序移动到Linux机器上时，我没有遇到同样的问题。这会告诉我，问题可能出在网络层而不是应用程序中。