pig to hadoop问题：服务器IPC版本7无法与客户端版本4通信

Question

我想让猪开始失败：

 $ pig
2013-05-10 18:03:22,972 [main] INFO  org.apache.pig.Main - Apache Pig version 0.11.1 (r1459641) compiled Mar 22 2013, 02:13:53
2013-05-10 18:03:22,972 [main] INFO  org.apache.pig.Main - Logging error messages to: /Users/barclaydunn/Environment/pig-0.11.1/pig_1368223402970.log
2013-05-10 18:03:23,151 [main] INFO  org.apache.pig.backend.hadoop.executionengine.HExecutionEngine - Connecting to hadoop file system at: hdfs://stage-hadoop101.cluster:8020/hbase
2013-05-10 18:03:23,704 [main] ERROR org.apache.pig.Main - ERROR 2999: Unexpected internal error. Failed to create DataStorage
Details at logfile: /Users/barclaydunn/Environment/pig-0.11.1/pig_1368223402970.log

日志文件内容：

 $ cat /Users/barclaydunn/Environment/pig-0.11.1/pig_1368223402970.log
Error before Pig is launched
----------------------------
ERROR 2999: Unexpected internal error. Failed to create DataStorage

java.lang.RuntimeException: Failed to create DataStorage
    at org.apache.pig.backend.hadoop.datastorage.HDataStorage.init(HDataStorage.java:75)
    at org.apache.pig.backend.hadoop.datastorage.HDataStorage.<init>(HDataStorage.java:58)
    at org.apache.pig.backend.hadoop.executionengine.HExecutionEngine.init(HExecutionEngine.java:204)
    at org.apache.pig.backend.hadoop.executionengine.HExecutionEngine.init(HExecutionEngine.java:117)
    at org.apache.pig.impl.PigContext.connect(PigContext.java:240)
    at org.apache.pig.PigServer.<init>(PigServer.java:213)
    at org.apache.pig.PigServer.<init>(PigServer.java:198)
    at org.apache.pig.tools.grunt.Grunt.<init>(Grunt.java:47)
    at org.apache.pig.Main.run(Main.java:535)
    at org.apache.pig.Main.main(Main.java:157)
    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.util.RunJar.main(RunJar.java:156)
Caused by: org.apache.hadoop.ipc.RemoteException: Server IPC version 7 cannot communicate with client version 4
    at org.apache.hadoop.ipc.Client.call(Client.java:1070)
    at org.apache.hadoop.ipc.RPC$Invoker.invoke(RPC.java:225)
    at com.sun.proxy.$Proxy1.getProtocolVersion(Unknown Source)
    at org.apache.hadoop.ipc.RPC.getProxy(RPC.java:396)
    at org.apache.hadoop.ipc.RPC.getProxy(RPC.java:379)
    at org.apache.hadoop.hdfs.DFSClient.createRPCNamenode(DFSClient.java:119)
    at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:238)
    at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:203)
    at org.apache.hadoop.hdfs.DistributedFileSystem.initialize(DistributedFileSystem.java:89)
    at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:1386)
    at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:66)
    at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:1404)
    at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:254)
    at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:123)
    at org.apache.pig.backend.hadoop.datastorage.HDataStorage.init(HDataStorage.java:72)
    ... 14 more
================================================================================

搜索“服务器IPC版本7无法与客户端版本4通信”并未发现任何有用的信息。

Answer 1

设置HADOOP_HOME指向您正在使用的hadoop。

从猪入门页面：

（您可以通过将HADOOP_HOME设置为指向安装Hadoop的目录来运行不同版本的Hadoop。如果您没有设置HADOOP_HOME，默认情况下Pig将使用嵌入式版本运行，目前是Hadoop 1.0.0。）

IPC版本4适用于Hadoop 1.0，而版本7适用于Hadoop 2.0，因此听起来您正在使用其嵌入式hadoop版本运行，但尝试与Hadoop 2集群通信。

Answer 2

当cdh3作业尝试与cdh4 HDFS通信时，可能会导致错误“服务器IPC版本7无法与客户端版本4通信”。

检查mapred.job.tracker和fs.default.name设置