我有一份工作，从内部部署的kafka获取消息，并使用Dataproc将其发送给BigQuery。但有时我会得到两个导致我的工作失败的例外情况。
ConnectionRefused ：
java.net.ConnectException: Call From <worker-3>/<ip> to <worker-1>:50267 failed on connection exception: java.net.ConnectException: Connection refused; For more details see: http://wiki.apache.org/hadoop/ConnectionRefused
at sun.reflect.GeneratedConstructorAccessor44.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at org.apache.hadoop.net.NetUtils.wrapWithMessage(NetUtils.java:792)
at org.apache.hadoop.net.NetUtils.wrapException(NetUtils.java:732)
at org.apache.hadoop.ipc.Client.call(Client.java:1480)
at org.apache.hadoop.ipc.Client.call(Client.java:1413)
at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:229)
at com.sun.proxy.$Proxy81.startContainers(Unknown Source)
at org.apache.hadoop.yarn.api.impl.pb.client.ContainerManagementProtocolPBClientImpl.startContainers(ContainerManagementProtocolPBClientImpl.java:96)
at sun.reflect.GeneratedMethodAccessor17.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:191)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:102)
at com.sun.proxy.$Proxy82.startContainers(Unknown Source)
at org.apache.hadoop.mapreduce.v2.app.launcher.ContainerLauncherImpl$Container.launch(ContainerLauncherImpl.java:151)
at org.apache.hadoop.mapreduce.v2.app.launcher.ContainerLauncherImpl$EventProcessor.run(ContainerLauncherImpl.java:375)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.net.ConnectException: Connection refused
at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:717)
at org.apache.hadoop.net.SocketIOWithTimeout.connect(SocketIOWithTimeout.java:206)
at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:531)
at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:495)
at org.apache.hadoop.ipc.Client$Connection.setupConnection(Client.java:615)
at org.apache.hadoop.ipc.Client$Connection.setupIOstreams(Client.java:713)
at org.apache.hadoop.ipc.Client$Connection.access$2900(Client.java:376)
at org.apache.hadoop.ipc.Client.getConnection(Client.java:1529)
at org.apache.hadoop.ipc.Client.call(Client.java:1452)
... 15 more
我查看了http://wiki.apache.org/hadoop/ConnectionRefused中列出的项目。
在例外情况下，我们可以看到：
“从 worker-3 / ip 致电 worker-1 ：50267”
未知端口上的工作人员之间的通信（？）（50267）
有时用：
“从主节点 / ip 致电主节点： 8020 ”
在NameNode元数据服务端口（8020）上的master中进行通信。
在另一个参考https://serverfault.com/questions/725262/what-causes-the-connection-refused-message上，它说：
消息'连接被拒绝'有两个主要原因：
- 没有人在监听IP：您尝试连接的端口。
- 端口被防火墙阻止。
这不应该由Dataproc处理吗？
由同行重置的连接：
Failed on local exception: java.io.IOException: Connection reset by peer; Host Details : local host is: "<master-node>/<ip>"; destination host is: "<master-node>":8020;
at org.apache.hadoop.net.NetUtils.wrapException(NetUtils.java:776)
at org.apache.hadoop.ipc.Client.call(Client.java:1479)
at org.apache.hadoop.ipc.Client.call(Client.java:1412)
at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:229)
at com.sun.proxy.$Proxy15.getFileInfo(Unknown Source)
at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.getFileInfo(ClientNamenodeProtocolTranslatorPB.java:771)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:191)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:102)
at com.sun.proxy.$Proxy16.getFileInfo(Unknown Source)
at org.apache.hadoop.hdfs.DFSClient.getFileInfo(DFSClient.java:2108)
at org.apache.hadoop.hdfs.DistributedFileSystem$22.doCall(DistributedFileSystem.java:1305)
at org.apache.hadoop.hdfs.DistributedFileSystem$22.doCall(DistributedFileSystem.java:1301)
at org.apache.hadoop.fs.FileSystemLinkResolver.resolve(FileSystemLinkResolver.java:81)
at org.apache.hadoop.hdfs.DistributedFileSystem.getFileStatus(DistributedFileSystem.java:1317)
at org.apache.hadoop.fs.FileSystem.exists(FileSystem.java:1426)
at gobblin.runtime.mapreduce.MRJobLauncher.<init>(MRJobLauncher.java:166)
at gobblin.runtime.mapreduce.CliMRJobLauncher.<init>(CliMRJobLauncher.java:59)
at gobblin.runtime.mapreduce.CliMRJobLauncher.main(CliMRJobLauncher.java:111)
... 5 more
Caused by: java.io.IOException: Connection reset by peer
at sun.nio.ch.FileDispatcherImpl.read0(Native Method)
at sun.nio.ch.SocketDispatcher.read(SocketDispatcher.java:39)
at sun.nio.ch.IOUtil.readIntoNativeBuffer(IOUtil.java:223)
at sun.nio.ch.IOUtil.read(IOUtil.java:197)
at sun.nio.ch.SocketChannelImpl.read(SocketChannelImpl.java:380)
at org.apache.hadoop.net.SocketInputStream$Reader.performIO(SocketInputStream.java:57)
at org.apache.hadoop.net.SocketIOWithTimeout.doIO(SocketIOWithTimeout.java:142)
at org.apache.hadoop.net.SocketInputStream.read(SocketInputStream.java:161)
at org.apache.hadoop.net.SocketInputStream.read(SocketInputStream.java:131)
at java.io.FilterInputStream.read(FilterInputStream.java:133)
at java.io.FilterInputStream.read(FilterInputStream.java:133)
at org.apache.hadoop.ipc.Client$Connection$PingInputStream.read(Client.java:520)
at java.io.BufferedInputStream.fill(BufferedInputStream.java:246)
at java.io.BufferedInputStream.read(BufferedInputStream.java:265)
at java.io.DataInputStream.readInt(DataInputStream.java:387)
at org.apache.hadoop.ipc.Client$Connection.receiveRpcResponse(Client.java:1084)
at org.apache.hadoop.ipc.Client$Connection.run(Client.java:979)
我的想法是，这两个错误都非常通用，并且发生在Dataproc集群内，与我的应用程序无关。我对么？我正在使用重试方法来解决我的问题。但我想了解为什么这些错误会出现在像Dataproc这样基于Hadoop的产品中，以及我是否有办法避免它们？ Dataproc不应该为用户处理所有这些事情吗？