exception: java.net.ConnectException: Connection refused; For more details see: http://wiki.apache.org/hadoop/ConnectionRefused
1、虽然，不是大错，还说要贴一下，由于我运行run-example streaming.NetworkWordCount localhost 9999的测试案例，出现的错误，第一感觉就是Spark没有启动导致的：
1 18/04/23 03:21:58 ERROR SparkContext: Error initializing SparkContext. 2 java.net.ConnectException: Call From slaver1/192.168.19.131 to slaver1:9000 failed on connection exception: java.net.ConnectException: Connection refused; For more details see: http://wiki.apache.org/hadoop/ConnectionRefused 3 at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) 4 at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57) 5 at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) 6 at java.lang.reflect.Constructor.newInstance(Constructor.java:526) 7 at org.apache.hadoop.net.NetUtils.wrapWithMessage(NetUtils.java:783) 8 at org.apache.hadoop.net.NetUtils.wrapException(NetUtils.java:730) 9 at org.apache.hadoop.ipc.Client.call(Client.java:1414) 10 at org.apache.hadoop.ipc.Client.call(Client.java:1363) 11 at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:206) 12 at com.sun.proxy.$Proxy12.getFileInfo(Unknown Source) 13 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 14 at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) 15 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) 16 at java.lang.reflect.Method.invoke(Method.java:606) 17 at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:190) 18 at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:103) 19 at com.sun.proxy.$Proxy12.getFileInfo(Unknown Source) 20 at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.getFileInfo(ClientNamenodeProtocolTranslatorPB.java:699) 21 at org.apache.hadoop.hdfs.DFSClient.getFileInfo(DFSClient.java:1762) 22 at org.apache.hadoop.hdfs.DistributedFileSystem$17.doCall(DistributedFileSystem.java:1124) 23 at org.apache.hadoop.hdfs.DistributedFileSystem$17.doCall(DistributedFileSystem.java:1120) 24 at org.apache.hadoop.fs.FileSystemLinkResolver.resolve(FileSystemLinkResolver.java:81) 25 at org.apache.hadoop.hdfs.DistributedFileSystem.getFileStatus(DistributedFileSystem.java:1120) 26 at org.apache.spark.scheduler.EventLoggingListener.start(EventLoggingListener.scala:100) 27 at org.apache.spark.SparkContext.<init>(SparkContext.scala:541) 28 at org.apache.spark.streaming.StreamingContext$.createNewSparkContext(StreamingContext.scala:864) 29 at org.apache.spark.streaming.StreamingContext.<init>(StreamingContext.scala:81) 30 at org.apache.spark.examples.streaming.NetworkWordCount$.main(NetworkWordCount.scala:47) 31 at org.apache.spark.examples.streaming.NetworkWordCount.main(NetworkWordCount.scala) 32 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 33 at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) 34 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) 35 at java.lang.reflect.Method.invoke(Method.java:606) 36 at org.apache.spark.deploy.SparkSubmit$.org$apache$spark$deploy$SparkSubmit$$runMain(SparkSubmit.scala:672) 37 at org.apache.spark.deploy.SparkSubmit$.doRunMain$1(SparkSubmit.scala:180) 38 at org.apache.spark.deploy.SparkSubmit$.submit(SparkSubmit.scala:205) 39 at org.apache.spark.deploy.SparkSubmit$.main(SparkSubmit.scala:120) 40 at org.apache.spark.deploy.SparkSubmit.main(SparkSubmit.scala) 41 Caused by: java.net.ConnectException: Connection refused 42 at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method) 43 at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:739) 44 at org.apache.hadoop.net.SocketIOWithTimeout.connect(SocketIOWithTimeout.java:206) 45 at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:529) 46 at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:493) 47 at org.apache.hadoop.ipc.Client$Connection.setupConnection(Client.java:604) 48 at org.apache.hadoop.ipc.Client$Connection.setupIOstreams(Client.java:699) 49 at org.apache.hadoop.ipc.Client$Connection.access$2800(Client.java:367) 50 at org.apache.hadoop.ipc.Client.getConnection(Client.java:1462) 51 at org.apache.hadoop.ipc.Client.call(Client.java:1381) 52 ... 31 more 53 18/04/23 03:21:59 INFO SparkUI: Stopped Spark web UI at http://192.168.19.131:4040 54 18/04/23 03:21:59 INFO DAGScheduler: Stopping DAGScheduler 55 18/04/23 03:21:59 INFO MapOutputTrackerMasterEndpoint: MapOutputTrackerMasterEndpoint stopped! 56 18/04/23 03:21:59 INFO MemoryStore: MemoryStore cleared 57 18/04/23 03:21:59 INFO BlockManager: BlockManager stopped 58 18/04/23 03:21:59 INFO BlockManagerMaster: BlockManagerMaster stopped 59 18/04/23 03:21:59 INFO SparkContext: Successfully stopped SparkContext 60 Exception in thread "main" java.net.ConnectException: Call From slaver1/192.168.19.131 to slaver1:9000 failed on connection exception: java.net.ConnectException: Connection refused; For more details see: http://wiki.apache.org/hadoop/ConnectionRefused 61 at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) 62 at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57) 63 at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) 64 at java.lang.reflect.Constructor.newInstance(Constructor.java:526) 65 at org.apache.hadoop.net.NetUtils.wrapWithMessage(NetUtils.java:783) 66 at org.apache.hadoop.net.NetUtils.wrapException(NetUtils.java:730) 67 at org.apache.hadoop.ipc.Client.call(Client.java:1414) 68 at org.apache.hadoop.ipc.Client.call(Client.java:1363) 69 at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:206) 70 at com.sun.proxy.$Proxy12.getFileInfo(Unknown Source) 71 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 72 at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) 73 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) 74 at java.lang.reflect.Method.invoke(Method.java:606) 75 at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:190) 76 at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:103) 77 at com.sun.proxy.$Proxy12.getFileInfo(Unknown Source) 78 at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.getFileInfo(ClientNamenodeProtocolTranslatorPB.java:699) 79 at org.apache.hadoop.hdfs.DFSClient.getFileInfo(DFSClient.java:1762) 80 at org.apache.hadoop.hdfs.DistributedFileSystem$17.doCall(DistributedFileSystem.java:1124) 81 at org.apache.hadoop.hdfs.DistributedFileSystem$17.doCall(DistributedFileSystem.java:1120) 82 at org.apache.hadoop.fs.FileSystemLinkResolver.resolve(FileSystemLinkResolver.java:81) 83 at org.apache.hadoop.hdfs.DistributedFileSystem.getFileStatus(DistributedFileSystem.java:1120) 84 at org.apache.spark.scheduler.EventLoggingListener.start(EventLoggingListener.scala:100) 85 at org.apache.spark.SparkContext.<init>(SparkContext.scala:541) 86 at org.apache.spark.streaming.StreamingContext$.createNewSparkContext(StreamingContext.scala:864) 87 at org.apache.spark.streaming.StreamingContext.<init>(StreamingContext.scala:81) 88 at org.apache.spark.examples.streaming.NetworkWordCount$.main(NetworkWordCount.scala:47) 89 at org.apache.spark.examples.streaming.NetworkWordCount.main(NetworkWordCount.scala) 90 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 91 at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) 92 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) 93 at java.lang.reflect.Method.invoke(Method.java:606) 94 at org.apache.spark.deploy.SparkSubmit$.org$apache$spark$deploy$SparkSubmit$$runMain(SparkSubmit.scala:672) 95 at org.apache.spark.deploy.SparkSubmit$.doRunMain$1(SparkSubmit.scala:180) 96 at org.apache.spark.deploy.SparkSubmit$.submit(SparkSubmit.scala:205) 97 at org.apache.spark.deploy.SparkSubmit$.main(SparkSubmit.scala:120) 98 at org.apache.spark.deploy.SparkSubmit.main(SparkSubmit.scala) 99 Caused by: java.net.ConnectException: Connection refused 100 at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method) 101 at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:739) 102 at org.apache.hadoop.net.SocketIOWithTimeout.connect(SocketIOWithTimeout.java:206) 103 at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:529) 104 at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:493) 105 at org.apache.hadoop.ipc.Client$Connection.setupConnection(Client.java:604) 106 at org.apache.hadoop.ipc.Client$Connection.setupIOstreams(Client.java:699) 107 at org.apache.hadoop.ipc.Client$Connection.access$2800(Client.java:367) 108 at org.apache.hadoop.ipc.Client.getConnection(Client.java:1462) 109 at org.apache.hadoop.ipc.Client.call(Client.java:1381) 110 ... 31 more 111 18/04/23 03:21:59 INFO OutputCommitCoordinator$OutputCommitCoordinatorEndpoint: OutputCommitCoordinator stopped! 112 18/04/23 03:21:59 INFO RemoteActorRefProvider$RemotingTerminator: Shutting down remote daemon. 113 18/04/23 03:21:59 INFO ShutdownHookManager: Shutdown hook called 114 18/04/23 03:21:59 INFO ShutdownHookManager: Deleting directory /tmp/spark-7ef5c2da-0b57-4553-a9f9-6e215885c7ba 115 18/04/23 03:21:59 INFO RemoteActorRefProvider$RemotingTerminator: Remote daemon shut down; proceeding with flushing remote transports.
2、启动Spark的脚本命令：
[hadoop@slaver1 spark-1.5.1-bin-hadoop2.4]$ sbin/start-all.sh
[hadoop@slaver2 ~]$ run-example streaming.NetworkWordCount localhost 9999
