《深入浅出pig系列之一》pig-0.12.0-cdh5.1.2的安装与运行
这里使用的版本是cdh发行的pig-0.12.0-cdh5.1.2 下载地址点这里
1.Pig简介：
Pig是yahoo捐献给apache的一个项目，它是SQL-like语言，是在MapReduce上构建的一种高级查询语言，把一些运算编译进MapReduce模型的Map和Reduce中，并且用户可以定义自己的功能。这是Yahoo开发的又一个克隆Google的项目:Sawzall。
Pig是一个客户端应用程序，就算你要在Hadoop集群上运行Pig，也不需要在集群上装额外的东西
2.安装
解压下载完成的pig到指定目录，我这里将其解压到用户hadoop目录下
hadoop@caozw:~/pig/conf$ tar -xzvf ~/Downloads/pig-0.12.0-cdh5.1.2.tar.gz -C ~/
为配置方便 这里将其建立软链接到pig
hadoop@caozw:~/pig/conf$ ln -s pig-0.12.0-cdh5.1.2/ pig
3.环境变量配置
通过编辑/etc/.profile文件或者是用户目录下面的～/.profile文件，我这里编辑hadoop用户目录下面的配置文件来配置
export PIG_HOME=/home/hadoop/pig
export PIG_CLASSPATH=${HADOOP_HOME}/etc/hadoop
export PATH=$PATH:$PIG_HOME/bin
其中PIG_CLASSPATH指定了hadoop的配置文件路径，本地模式不要配置，如果需要访问hadoop的时候必须配置
通过source ～/.profile使配置生效
4.local运行
hadoop@caozw:~/pig/conf$ pig -x local
2014-10-13 19:17:34,862 [main] INFO org.apache.pig.Main - Apache Pig version 0.12.0-cdh5.1.2 (rexported) compiled Aug 25 2014, 19:51:48
2014-10-13 19:17:34,863 [main] INFO org.apache.pig.Main - Logging error messages to: /home/hadoop/pig-0.12.0-cdh5.1.2/conf/pig_1413199054861.log
2014-10-13 19:17:34,905 [main] INFO org.apache.pig.impl.util.Utils - Default bootup file /home/hadoop/.pigbootup not found
2014-10-13 19:17:35,204 [main] INFO org.apache.hadoop.conf.Configuration.deprecation - fs.default.name is deprecated. Instead, use fs.defaultFS
2014-10-13 19:17:35,205 [main] INFO org.apache.hadoop.conf.Configuration.deprecation - mapred.job.tracker is deprecated. Instead, use mapreduce.jobtracker.address
2014-10-13 19:17:35,206 [main] INFO org.apache.pig.backend.hadoop.executionengine.HExecutionEngine - Connecting to hadoop file system at: file:///
SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/home/hadoop/hadoop-2.3.0-cdh5.1.2/share/hadoop/common/lib/slf4j-log4j12-1.7.5.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/hadoop/hbase-0.98.1-cdh5.1.2/lib/slf4j-log4j12-1.7.5.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
SLF4J: Actual binding is of type [org.slf4j.impl.Log4jLoggerFactory]
2014-10-13 19:17:35,732 [main] WARN org.apache.hadoop.util.NativeCodeLoader - Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
2014-10-13 19:17:35,918 [main] INFO org.apache.hadoop.conf.Configuration.deprecation - io.bytes.per.checksum is deprecated. Instead, use dfs.bytes-per-checksum
2014-10-13 19:17:35,922 [main] INFO org.apache.hadoop.conf.Configuration.deprecation - fs.default.name is deprecated. Instead, use fs.defaultFS
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5.hadoop运行
需要启动hadoop集群，pig会根据PIG_CLASSPATH的路径下面的配置文件自动识别hadoop集群
grunt> hadoop@caozw:~/pig/conf$ pig
2014-10-13 19:18:36,511 [main] INFO org.apache.pig.Main - Apache Pig version 0.12.0-cdh5.1.2 (rexported) compiled Aug 25 2014, 19:51:48
2014-10-13 19:18:36,511 [main] INFO org.apache.pig.Main - Logging error messages to: /home/hadoop/pig-0.12.0-cdh5.1.2/conf/pig_1413199116510.log
2014-10-13 19:18:36,541 [main] INFO org.apache.pig.impl.util.Utils - Default bootup file /home/hadoop/.pigbootup not found
2014-10-13 19:18:36,849 [main] INFO org.apache.hadoop.conf.Configuration.deprecation - mapred.job.tracker is deprecated. Instead, use mapreduce.jobtracker.address
2014-10-13 19:18:36,849 [main] INFO org.apache.hadoop.conf.Configuration.deprecation - fs.default.name is deprecated. Instead, use fs.defaultFS
2014-10-13 19:18:36,849 [main] INFO org.apache.pig.backend.hadoop.executionengine.HExecutionEngine - Connecting to hadoop file system at: hdfs://192.168.118.168:9100
SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/home/hadoop/hadoop-2.3.0-cdh5.1.2/share/hadoop/common/lib/slf4j-log4j12-1.7.5.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/hadoop/hbase-0.98.1-cdh5.1.2/lib/slf4j-log4j12-1.7.5.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
SLF4J: Actual binding is of type [org.slf4j.impl.Log4jLoggerFactory]
2014-10-13 19:18:37,071 [main] WARN org.apache.hadoop.util.NativeCodeLoader - Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
2014-10-13 19:18:38,379 [main] INFO org.apache.hadoop.conf.Configuration.deprecation - fs.default.name is deprecated. Instead, use fs.defaultFS
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