Question

我在两台机器上配置了hadoop。我可以使用ssh.i使用以下命令成功格式化namenode来访问两台没有密码的机器： -

bin/hadoop namenode -format

然后我尝试运行带有hadoop.tar

的pi示例

sandip@master:~/hadoop-1.0.4$ bin/hadoop jar hadoop-examples-1.0.4.jar pi 5 500
Number of Maps  = 5
Samples per Map = 500
13/04/14 04:13:04 INFO ipc.Client: Retrying connect to server:       
master/192.168.188.131:9000. Already tried 0 time(s).
13/04/14 04:13:05 INFO ipc.Client: Retrying connect to server:                         
master/192.168.188.131:9000. Already tried 1 time(s).
13/04/14 04:13:06 INFO ipc.Client: Retrying connect to server:     
master/192.168.188.131:9000. Already tried 2 time(s).
13/04/14 04:13:07 INFO ipc.Client: Retrying connect to server:   
master/192.168.188.131:9000. Already tried 3 time(s).
13/04/14 04:13:08 INFO ipc.Client: Retrying connect to server:   
master/192.168.188.131:9000. Already tried 4 time(s).
13/04/14 04:13:09 INFO ipc.Client: Retrying connect to server:      
master/192.168.188.131:9000. Already tried 5 time(s).
13/04/14 04:13:10 INFO ipc.Client: Retrying connect to server:     
master/192.168.188.131:9000. Already tried 6 time(s).
13/04/14 04:13:11 INFO ipc.Client: Retrying connect to server:   
master/192.168.188.131:9000. Already tried 7 time(s).
13/04/14 04:13:12 INFO ipc.Client: Retrying connect to server:   
master/192.168.188.131:9000. Already tried 8 time(s).
13/04/14 04:13:13 INFO ipc.Client: Retrying connect to server:    
master/192.168.188.131:9000. Already tried 9 time(s).
java.lang.RuntimeException: java.net.ConnectException: Call to    
master/192.168.188.131:9000 failed on connection exception: java.net.ConnectException:    
Connection refused
at org.apache.hadoop.mapred.JobConf.getWorkingDirectory(JobConf.java:546)
at org.apache.hadoop.mapred.FileInputFormat.setInputPaths(FileInputFormat.java:318)
at org.apache.hadoop.examples.PiEstimator.estimate(PiEstimator.java:265)
at org.apache.hadoop.examples.PiEstimator.run(PiEstimator.java:342)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:65)
at org.apache.hadoop.examples.PiEstimator.main(PiEstimator.java:351)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at     
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at 
 org.apache.hadoop.util.ProgramDriver$ProgramDescription.invoke(ProgramDriver.java:68)
at org.apache.hadoop.util.ProgramDriver.driver(ProgramDriver.java:139)
at org.apache.hadoop.examples.ExampleDriver.main(ExampleDriver.java:64)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at

Answer 1

是的，我忘了启动hadoop集群。我通过运行此命令修复了它： -

仓/ start-all.sh

Answer 2

它说：连接被拒绝了。通过查看日志，我可以说在启动集群时，您的计算机无法连接到namenode。

检查以下事项： - 名称节点地址是正确的（您使用core-site.xml中的default.fs.name给它） - 检查mapred-site.xml中是否指定了任务跟踪器的正确地址 - 检查是否在core-site.xml中指定了hadoop.tmp.dir属性。格式化后，您的计算机上会存在此目录。

- 格式化之后再验证一件事是VERSION文件应该在主节点和从节点中包含相同的名称空间ID。

运行hadoop pi示例时java.lang.runtimeexception java.net.connectexception

2 个答案: