cloudera hadoop setup

Setup function source code: (Excerpt from "Hadoop Combat")*called once at the start of the task.protected void Setup (context context) throws ioexception,interruptedexception{}As you can tell from the comments, the setup function is called when the task starts.Jobs in MapReduce are organized into Maptask and Reducetask

file./hdfs/data--Storing data./hdfs/tmp--Storing temporary files　　　2.6 Modifying an XML configuration file　 The XML file that needs to be modified under hadoop2.9.1/etc/hadoop/There are 5 main files to modify:hadoop-env.shCore-site.xmlHdfs-site.xmlMapred-site.xmlYarn-site.xmlSlaves　　　　　2.6.1, vim hadoop-env.sh, fill in the Java installation path　　　　　　　　　　2.6.2, vim core-site.xml,configuration tag insert t

1. Need to install package 1.1 Hadoop source Package (hadoop-2.5.2-src.tar.gz) 1.2 Hadoop 2X plug-in (hadoop2x-eclipse-plugin-master.zip) 1.3 Hadoop window S tool (Hadoop-common-2.2.0-bin-master.zip) 1.4 Ant Compilation Tool (APACHE-ANT-1.9.6.TAR.GZ) 2. Steps (the JDK and Ec

Today to open an account to configure Hadoop, but all finished, run, there is no Java found in the case, my Java is set in the. ZSHRC, export Java_home=/usr/lib/jvm/java, in the original is available, But not this time, and then found the solution on the Internet, into the hadoop/libexec/hadoop-config.sh, and then #attempt to set Java_home if it no set before add

The role of Setup run cleanup context in Hadoop execution1. Introduction1) Setup (), this method is only executed once by the MapReduce framework and performs a centralized initialization of the relevant variables or resources before performing the map task. If the resource initialization work is placed in the method map (), causing the mapper task to parse each

1. ConfigurationNamenode Hdfs-site.xml is the Dfs.webhdfs.enabled property must be set to true, otherwise you will not be able to use Webhdfs liststatus, listfilestatus, etc. need to list files, The folder Status command, because this information is saved by Namenode.Add attributes to/etc/hadoop/conf/hdfs-site.xml in Namenode and one datanode:2. Instructions for useAccess Namenode HDFs using port 50070, Access Datanode Webhdfs using 50075 ports. Acces

Always focused on Hadoop projects, and recently found that you can build Hadoop under Windows.decided to give it a try. The gossip is less.Prepare a Windows 7 32-bit environment first,(official online said does not support 64-bit, compile will be problematic, not to say why, if you want to use on the Windows 64-bit machine, you can compile in 32-bit environment to 64-bit, and then deploy to 64-bit machine)R

Step OneIf not, do not set up the HBase development environment blog, see my next blog.HBase Development Environment Building (Eclipse\myeclipse + Maven)　　Step one, need to add. As follows:In the project name, right-click,Then, write Pom.xml, here not much to repeat. SeeHBase Development Environment Building (Eclipse\myeclipse + Maven)When you are done, write the code, right.Step two some steps after the HBase development environment is built (export exported jar package or Ant mode)Here, do not