摘要：

How to Install Hadoop?(On Mac OS, Linux or Cygwin on Windows)1)Download hadoop 0.20.0 from http://hadoop.apache.org/mapreduce/releases.html2)Untar the hadoop file:tar xvfz hadoop-0.20.2.tar.gz3)Set the path to java compiler by editing JAVA_HOME parameter in hadoop/conf/hadoop-­‐env.sh:Mac OS users can use /System/Library/Frameworks/JavaVM.framework/Versions/1.6.0/HomeLinux users can run "which java" command to obtain the path. Note that the JAVA_HOME variable shouldn't contain the bin/java at the end of path.4)Create an RSA key to be used by hadoop when ssh'ing to localhost:ssh-keygen-t rsa-P""cat~/.ssh/id_rsa.pub >>~/.ssh/authorized_keys5)Do the following changes to the configuration files under hadoop/confcore-­site.xml:hadoop.tmp.dirTEMPORARY-DIR-FOR-HADOOP-DATASTOREfs.default.namehdfs://localhost:54310mapred-­site.xml:mapred.job.trackerlocalhost:54311hdfs-­site.xml:dfs.replication16)Format the hadoop file system. From hadoop directory run the following:./bin/hadoop namenode-format7)Run hadoop by running the following script:./bin/start-all.sh8)Now you can copy some data from your machine's file system into hdfs and do 'ls' command on hdfs:./bin/hadoop dfs–put local_machine_path hdfs_path./bin/hadoop dfs-ls9)At this point you are ready to run a map reduce job on hadoop. As an example, let's run WordCount.jar to count the number of times each word appears in a text file. Put a sample text file on hdfs under 'input'directory. Download the jar file from: http://www.stanford.edu/class/cs246/cs246-­‐11-­‐mmds/hw_files/WordCount.jarand run the WordCount map-­‐reduce job:./bin/hadoopdfs–mkdir input./bin/hadoop dfs–put local_machine_path/sample.txt input/sample.txt./bin/hadoop jar ~/path_to_jar_file/WordCount.jar WordCount inputoutputThe result will be saved on 'output' directory on hdfs.References:http://arifn.web.id/blog/2010/07/29/running-­‐hadoop-­‐single-­‐cluster.htmlhttp://arifn.web.id/blog/2010/01/23/hadoop-­‐in-­‐netbeans.htmlhttp://www.infosci.cornell.edu/hadoop/mac.htmlhttp://wiki.apache.org/hadoop/GettingStartedWithHadoop

展开