hadoop analytics example

Immediately after the completion of the installation and running of Hadoop, it is time to run the relevant example, and the simplest and most straightforward example is the HelloWorld-wordcount example. Follow the blog to run: http://xiejianglei163.blog.163.com/blog/static/1247276201443152533684/ First create a folde

#pi值示例hadoop Jar/app/cdh23502/share/hadoop/mapreduce2/hadoop-mapreduce-examples-2.3.0-cdh5.0.2. Jar PI - $#生成数据 The first parameter is the number of rows the second parameter is the location of the Hadoop jar/app/cdh23502/share/hadoop/mapreduce2/

Document directory 1. Map stage 3. Let's take a general look at the Running code of the job: This series of hadoop learning notes is based on hadoop: the definitive guide 3th, which collects additional information on the Internet and displays hadoop APIs, and adds its ownPracticeIs mainly used to learn the features and functions of

=131Reduce Input groups=131Reduce Shuffle bytes=1836Reduce Input records=131Reduce Output records=131For:warn-unable to load Native-hadoop library for your platform ... using Builtin-java classes where applicable this warning is fine, run It's not reported on Linux.8.Finally, try to split the wordcount into subclasses and move the mapper out of the way, because sometimes multiple classes will prompt for an error:Delete Output directory, rerun: OK, no

I used to write some mapreduce programs in Java. Here's an example of using Python to implement MapReduce via Hadoop streaming.Task Description:There are two directories on HDFS/A and/b, there are 3 columns in the data, the first column is the ID, the second column is the respective business type (this assumes the/a corresponds to a,/b b), and the third column is a JSON string. One

;ImportOrg.apache.hadoop.conf.Configuration;ImportOrg.apache.hadoop.io.Text;ImportOrg.apache.hadoop.ipc.RPC; Public class rpcclient { PrivateMyrpcprotocal protocal; Public rpcclient()throwsexception{inetsocketaddress address =NewInetsocketaddress ("localhost",9999); Protocal = (myrpcprotocal) rpc.waitforproxy (Myrpcprotocal.class,myrpcprotocal.versionid, address,NewConfiguration ());//rpc.setprotocolengine (New Configuration (), Myrpcprotocal.class, rpcengine.class);} Public void Pager(Strin

] Ssh-copy-id–i ~/.ssh/id_rsa.pub [email protected] The purpose of this is to SSH from Hadoopnamenode to the other three servers without requiring a password. After Ssh-copy-id, the public key is actually added to the other three server ~/.ssh/authorized_keys files.For example, to log in to Hadoop2ndnamenode from Hadoopnamenode, the process is probably: Hadoop2ndnamenode sends a random string to Hadoopnamenode, and Hadoopnamenode encrypts it

;ImportOrg.apache.hadoop.mapreduce.Job;ImportOrg.apache.hadoop.mapreduce.Mapper;ImportOrg.apache.hadoop.mapreduce.Reducer;ImportOrg.apache.hadoop.mapreduce.lib.input.FileInputFormat;ImportOrg.apache.hadoop.mapreduce.lib.output.FileOutputFormat;ImportOrg.apache.hadoop.util.GenericOptionsParser;/*** Description: WordCount explains by York *@authorHadoop Dev Group*/publicclass WordCount {/*** Build Mapper class tokenizermapper inherit from generic class Mapper * Mapper class: Implements the Map fun