A)版本
hadoop-1.0.3
jdk1.6.0_32
eclipse hadoop开发插件hadoop-eclipse-plugin-1.0.3.jar
hadoop-1.0.3 使用单机模式安装, 端口hdfs 9000 mapred 9001
B)环境
1) hadoop-1.0.3 的安装步骤 可以参照http://hadoop.apache.org/docs/r1.0.3/single_node_setup.html
conf/core-site.xml
<?xml version="1.0"?> <?xml-stylesheet type="text/xsl" href="configuration.xsl"?> <!-- Put site-specific property overrides in this file. --> <configuration> <property> <name>fs.default.name</name> <value>hdfs://xxx.xxx.xxx.xxx:9000</value> </property> <property> <name>hadoop.tmp.dir</name> <value>/opt/hadoop-1.0.3/tmp</value> </property> </configuration>
conf/mapred-site.xml:
<configuration>
<property>
<name>mapred.job.tracker</name>
<value>xxx.xxx.xxx.xxx:9001</value>
</property>
</configuration>
conf/hdfs-site.xml
<?xml version="1.0"?> <?xml-stylesheet type="text/xsl" href="configuration.xsl"?> <!-- Put site-specific property overrides in this file. --> <configuration> <property> <name>dfs.replication</name> <value>1</value> </property> <property> <name>dfs.permissions</name> <value>false</value> </property> </configuration>
2)开发
1、用的是WINDOWS 下的 Eclipse,将插件复制到plugin目录里就可以了
2、将hadoop-1.0.3 解压到程序员的开发机器上
3、设置Hadoop Map/Reduce到你解压的目录
4、配置Map/Reduce Location
5、
新建Map/Reduce工程
examples\org\apache\hadoop\examples中的WordCount.java导入到工程里
问题出来了 直接运行的话 会提示权限问题。
12/09/24 13:52:27 ERROR security.UserGroupInformation: PriviledgedActionException as:zzj cause:java.io.IOException: Failed to set permissions of path: \tmp\hadoop-zzj\mapred\staging\zzj-743566479\.staging to 0700
Exception in thread "main" java.io.IOException: Failed to set permissions of path: \tmp\hadoop-zzj\mapred\staging\zzj-743566479\.staging to 0700
处理这个问题可以直接使用。
conf.set("mapred.job.tracker", "218.249.75.144:9001");来手工指定
用RunAS 选择 Run on Hadoop运行这个工程。eclipse 会自动将Jar包传输到Hadoop上并运行