我正在尝试设置一个多节点 Hadoop 集群。现在，我只尝试使用两个节点。一个是NameNode/DataNode（主机A），另一个是第二个DataNode（主机B）。奇怪的是，我只能从主机 A 或主机 B 运行一个 DataNode。如果我从 conf/slaves 文件中删除主机 B，并且只保留主机 A，系统将使用主机 A作为数据节点。但是如果我将主机 A 和 B 都放在 conf/slaves 文件中，那么只有主机 B 会显示为系统中唯一的 DataNode。
以下是主机A不工作时的日志：
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2013-07-31 10:18:16,074 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: STARTUP_MSG:
/************************************************************
STARTUP_MSG: Starting DataNode
STARTUP_MSG: host = A.MYDOMAIN.com/192.168.1.129
STARTUP_MSG: args = []
STARTUP_MSG: version = 1.0.4
STARTUP_MSG: build = https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1.0 -r 1393290; compiled by 'hortonfo' on Wed Oct 3 05:13:58 UTC 2012
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2013-07-31 10:18:16,317 INFO org.apache.hadoop.metrics2.impl.MetricsConfig: loaded properties from hadoop-metrics2.properties
2013-07-31 10:18:16,334 INFO org.apache.hadoop.metrics2.impl.MetricsSourceAdapter: MBean for source MetricsSystem,sub=Stats registered.
2013-07-31 10:18:16,335 INFO org.apache.hadoop.metrics2.impl.MetricsSystemImpl: Scheduled snapshot period at 10 second(s).
2013-07-31 10:18:16,335 INFO org.apache.hadoop.metrics2.impl.MetricsSystemImpl: DataNode metrics system started
2013-07-31 10:18:16,470 INFO org.apache.hadoop.metrics2.impl.MetricsSourceAdapter: MBean for source ugi registered.
2013-07-31 10:18:16,842 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Registered FSDatasetStatusMBean
2013-07-31 10:18:16,855 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Opened info server at 50010
2013-07-31 10:18:16,858 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Balancing bandwith is 1048576 bytes/s
2013-07-31 10:18:16,932 INFO org.mortbay.log: Logging to org.slf4j.impl.Log4jLoggerAdapter(org.mortbay.log) via org.mortbay.log.Slf4jLog
2013-07-31 10:18:17,038 INFO org.apache.hadoop.http.HttpServer: Added global filtersafety (class=org.apache.hadoop.http.HttpServer$QuotingInputFilter)
2013-07-31 10:18:17,053 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: dfs.webhdfs.enabled = false
2013-07-31 10:18:17,054 INFO org.apache.hadoop.http.HttpServer: Port returned by webServer.getConnectors()[0].getLocalPort() before open() is -1. Opening the listener on 50075
2013-07-31 10:18:17,054 INFO org.apache.hadoop.http.HttpServer: listener.getLocalPort() returned 50075 webServer.getConnectors()[0].getLocalPort() returned 50075
2013-07-31 10:18:17,054 INFO org.apache.hadoop.http.HttpServer: Jetty bound to port 50075
2013-07-31 10:18:17,054 INFO org.mortbay.log: jetty-6.1.26
2013-07-31 10:18:17,437 INFO org.mortbay.log: Started SelectChannelConnector@0.0.0.0:50075
2013-07-31 10:18:17,444 INFO org.apache.hadoop.metrics2.impl.MetricsSourceAdapter: MBean for source jvm registered.
2013-07-31 10:18:17,446 INFO org.apache.hadoop.metrics2.impl.MetricsSourceAdapter: MBean for source DataNode registered.
2013-07-31 10:18:17,786 INFO org.apache.hadoop.ipc.Server: Starting SocketReader
2013-07-31 10:18:17,790 INFO org.apache.hadoop.metrics2.impl.MetricsSourceAdapter: MBean for source RpcDetailedActivityForPort50020 registered.
2013-07-31 10:18:17,791 INFO org.apache.hadoop.metrics2.impl.MetricsSourceAdapter: MBean for source RpcActivityForPort50020 registered.
2013-07-31 10:18:17,794 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: dnRegistration = DatanodeRegistration(A.MYDOMAIN.com:50010, storageID=DS-1991287861-192.168.1.129-50010-1373314691613, infoPort=50075, ipcPort=50020)
2013-07-31 10:18:17,817 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Starting asynchronous block report scan
2013-07-31 10:18:17,820 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: DatanodeRegistration(192.168.1.129:50010, storageID=DS-1991287861-192.168.1.129-50010-1373314691613, infoPort=50075, ipcPort=50020)In DataNode.run, data = FSDataset{dirpath='/disk2/clustering/support/hdfs/data/current'}
2013-07-31 10:18:17,824 INFO org.apache.hadoop.ipc.Server: IPC Server Responder: starting
2013-07-31 10:18:17,825 INFO org.apache.hadoop.ipc.Server: IPC Server listener on 50020: starting
2013-07-31 10:18:17,827 INFO org.apache.hadoop.ipc.Server: IPC Server handler 0 on 50020: starting
2013-07-31 10:18:17,827 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: using BLOCKREPORT_INTERVAL of 3600000msec Initial delay: 0msec
2013-07-31 10:18:17,829 INFO org.apache.hadoop.ipc.Server: IPC Server handler 1 on 50020: starting
2013-07-31 10:18:17,830 INFO org.apache.hadoop.ipc.Server: IPC Server handler 2 on 50020: starting
2013-07-31 10:18:17,831 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Starting Periodic block scanner.
2013-07-31 10:18:17,831 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Finished asynchronous block report scan in 14ms
2013-07-31 10:18:17,845 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Generated rough (lockless) block report in 12 ms
2013-07-31 10:18:17,848 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Reconciled asynchronous block report against current state in 2 ms
2013-07-31 10:18:20,828 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Reconciled asynchronous block report against current state in 0 ms
2013-07-31 10:18:20,838 WARN org.apache.hadoop.hdfs.server.datanode.DataNode: DataNode is shutting down: org.apache.hadoop.ipc.RemoteException: org.apache.hadoop.hdfs.protocol.UnregisteredDatanodeException: Data node 192.168.1.129:50010 is attempting to report storage ID DS-1991287861-192.168.1.129-50010-1373314691613. Node 192.168.1.128:50010 is expected to serve this storage.
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.getDatanode(FSNamesystem.java:4608)
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.processReport(FSNamesystem.java:3460)
at org.apache.hadoop.hdfs.server.namenode.NameNode.blockReport(NameNode.java:1001)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:563)
at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:1388)
at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:1384)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:396)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1121)
at org.apache.hadoop.ipc.Server$Handler.run(Server.java:1382)
at org.apache.hadoop.ipc.Client.call(Client.java:1070)
at org.apache.hadoop.ipc.RPC$Invoker.invoke(RPC.java:225)
at $Proxy5.blockReport(Unknown Source)
at org.apache.hadoop.hdfs.server.datanode.DataNode.offerService(DataNode.java:958)
at org.apache.hadoop.hdfs.server.datanode.DataNode.run(DataNode.java:1458)
at java.lang.Thread.run(Thread.java:662)
2013-07-31 10:18:20,839 INFO org.mortbay.log: Stopped SelectChannelConnector@0.0.0.0:50075
2013-07-31 10:18:20,942 INFO org.apache.hadoop.ipc.Server: Stopping server on 50020
2013-07-31 10:18:20,943 INFO org.apache.hadoop.ipc.Server: IPC Server handler 0 on 50020: exiting
2013-07-31 10:18:20,944 INFO org.apache.hadoop.ipc.Server: IPC Server handler 2 on 50020: exiting
2013-07-31 10:18:20,944 INFO org.apache.hadoop.ipc.Server: Stopping IPC Server listener on 50020
2013-07-31 10:18:20,943 INFO org.apache.hadoop.ipc.Server: IPC Server handler 1 on 50020: exiting
2013-07-31 10:18:20,945 INFO org.apache.hadoop.ipc.metrics.RpcInstrumentation: shut down
2013-07-31 10:18:20,945 INFO org.apache.hadoop.ipc.Server: Stopping IPC Server Responder
2013-07-31 10:18:20,945 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Waiting for threadgroup to exit, active threads is 1
2013-07-31 10:18:20,945 WARN org.apache.hadoop.hdfs.server.datanode.DataNode: DatanodeRegistration(192.168.1.129:50010, storageID=DS-1991287861-192.168.1.129-50010-1373314691613, infoPort=50075, ipcPort=50020):DataXceiveServer:java.nio.channels.AsynchronousCloseException
at java.nio.channels.spi.AbstractInterruptibleChannel.end(AbstractInterruptibleChannel.java:185)
at sun.nio.ch.ServerSocketChannelImpl.accept(ServerSocketChannelImpl.java:157)
at sun.nio.ch.ServerSocketAdaptor.accept(ServerSocketAdaptor.java:84)
at org.apache.hadoop.hdfs.server.datanode.DataXceiverServer.run(DataXceiverServer.java:131)
at java.lang.Thread.run(Thread.java:662)
2013-07-31 10:18:20,945 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Exiting DataXceiveServer
2013-07-31 10:18:21,905 INFO org.apache.hadoop.hdfs.server.datanode.DataBlockScanner: Exiting DataBlockScanner thread.
2013-07-31 10:18:21,945 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Waiting for threadgroup to exit, active threads is 0
2013-07-31 10:18:22,047 INFO org.apache.hadoop.hdfs.server.datanode.FSDatasetAsyncDiskService: Shutting down all async disk service threads...
2013-07-31 10:18:22,048 INFO org.apache.hadoop.hdfs.server.datanode.FSDatasetAsyncDiskService: All async disk service threads have been shut down.
2013-07-31 10:18:22,048 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: DatanodeRegistration(192.168.1.129:50010, storageID=DS-1991287861-192.168.1.129-50010-1373314691613, infoPort=50075, ipcPort=50020):Finishing DataNode in: FSDataset{dirpath='/disk2/clustering/support/hdfs/data/current'}
2013-07-31 10:18:22,050 WARN org.apache.hadoop.metrics2.util.MBeans: Hadoop:service=DataNode,name=DataNodeInfo
javax.management.InstanceNotFoundException: Hadoop:service=DataNode,name=DataNodeInfo
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.getMBean(DefaultMBeanServerInterceptor.java:1094)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.exclusiveUnregisterMBean(DefaultMBeanServerInterceptor.java:415)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.unregisterMBean(DefaultMBeanServerInterceptor.java:403)
at com.sun.jmx.mbeanserver.JmxMBeanServer.unregisterMBean(JmxMBeanServer.java:506)
at org.apache.hadoop.metrics2.util.MBeans.unregister(MBeans.java:71)
at org.apache.hadoop.hdfs.server.datanode.DataNode.unRegisterMXBean(DataNode.java:522)
at org.apache.hadoop.hdfs.server.datanode.DataNode.shutdown(DataNode.java:737)
at org.apache.hadoop.hdfs.server.datanode.DataNode.run(DataNode.java:1471)
at java.lang.Thread.run(Thread.java:662)
2013-07-31 10:18:22,051 INFO org.apache.hadoop.ipc.Server: Stopping server on 50020
2013-07-31 10:18:22,051 INFO org.apache.hadoop.ipc.metrics.RpcInstrumentation: shut down
2013-07-31 10:18:22,051 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Waiting for threadgroup to exit, active threads is 0
2013-07-31 10:18:22,051 WARN org.apache.hadoop.metrics2.util.MBeans: Hadoop:service=DataNode,name=FSDatasetState-DS-1991287861-192.168.1.129-50010-1373314691613
javax.management.InstanceNotFoundException: Hadoop:service=DataNode,name=FSDatasetState-DS-1991287861-192.168.1.129-50010-1373314691613
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.getMBean(DefaultMBeanServerInterceptor.java:1094)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.exclusiveUnregisterMBean(DefaultMBeanServerInterceptor.java:415)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.unregisterMBean(DefaultMBeanServerInterceptor.java:403)
at com.sun.jmx.mbeanserver.JmxMBeanServer.unregisterMBean(JmxMBeanServer.java:506)
at org.apache.hadoop.metrics2.util.MBeans.unregister(MBeans.java:71)
at org.apache.hadoop.hdfs.server.datanode.FSDataset.shutdown(FSDataset.java:2067)
at org.apache.hadoop.hdfs.server.datanode.DataNode.shutdown(DataNode.java:799)
at org.apache.hadoop.hdfs.server.datanode.DataNode.run(DataNode.java:1471)
at java.lang.Thread.run(Thread.java:662)
2013-07-31 10:18:22,052 WARN org.apache.hadoop.hdfs.server.datanode.FSDatasetAsyncDiskService: AsyncDiskService has already shut down.
2013-07-31 10:18:22,052 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Exiting Datanode
2013-07-31 10:18:22,055 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: SHUTDOWN_MSG:
/************************************************************
SHUTDOWN_MSG: Shutting down DataNode at A.MYDOMAIN.com/192.168.1.129
我将不胜感激任何见解。谢谢。
编辑：配置文件如下：
core-site.xml
<configuration>
<property>
<name>fs.default.name</name>
<value>hdfs://A.MYDOMAIN.COM:9000</value>
</property>
</configuration>
hdfs-site.xml
<configuration>
<property>
<name>dfs.replication</name>
<value>2</value>
</property>
<property>
<name>dfs.data.dir</name>
<value>/disk2/clustering/support/hdfs/data</value>
</property>
<property>
<name>dfs.name.dir</name>
<value>/disk2/clustering/support/hdfs/name</value>
</property>
<property>
<name>hadoop.tmp.dir</name>
<value>/disk2/clustering/support/hdfs/tmp</value>
</property>
</configuration>
slaves (on host A only, host B is default localhost)
A.MYDOMAIN.COM
B.MYDOMAIN.COM
masters (on host A only, host B is default localhost)
A.MYDOMAIN.COM
更新：刚刚将另一台主机 C 添加到集群中，并使主机 A 仅用作 NameNode（不是 NameNode/DataNode）。问题是一样的。只有 1 个主机可以作为 DataNode 运行。有任何想法吗？非常感谢。