hadoop prerequisites

Hadoop is a platform for storing massive amounts of data on distributed server clusters and running distributed analytics applications, with the core components of HDFS and MapReduce. HDFS is a distributed file system that can read distributed storage of data systems;MapReduce is a computational framework that distributes computing tasks based on Task Scheduler by splitting computing tasks. Hadoop is an ess

Reprinted from http://blessht.iteye.com/blog/2095675Hadoop has always been the technology I want to learn, just as the recent project team to do e-mall, I began to study Hadoop, although the final identification of Hadoop is not suitable for our project, but I will continue to study, more and more do not press.The basic Hadoop tutorial is the first

Hadoop version 1.2.1 Jdk1.7.0 Example 3-1: Use the urlstreamhandler instance to display files of the hadoop File System in standard output mode hadoop fs -mkdir input Create two files, file1, file2, and file1, as Hello world, and file2 as Hello hadoop, and then upload the files to the input file. The specific method i

Wang Jialin's in-depth case-driven practice of cloud computing distributed Big Data hadoop in July 6-7 in Shanghai This section describes how to use the HDFS command line tool to operate hadoop distributed clusters: Step 1: Use the hsfs command to store a large file in a hadoop distributed cluster; Step 2: delete the file and use two copies to s

9 install hadoop Tar-zvxf hadoop-1.1.2.tar.gz Music hadoop-1.1.2/usr/lib/hadoop Run gedit/etc/profile to add and modify it: Export java_home =/usr/lib/JVM Export hadoop_home =/usr/lib/hadoop/ Export Path =.: $ java_home/bin: $ hadoop_home/bin: $ path Source/etc/profile 10 co

Hadoop Study Notes 0004 -- Eclipse installation Hadoop Plugins1 , download hadoop-1.2.1.tar.gz , unzip to Win7 under hadoop-1.2.1 ;2 , if hadoop-1.2.1 not in Hadoop-eclipse-plugin-1.2.1.jar package, on the internet to download d

Hadoop can be run in stand-alone mode or in pseudo-distributed mode, both of which are designed for users to easily learn and debug Hadoop, and to exploit the benefits of distributed Hadoop, parallel processing, and deploy Hadoop in distributed mode. Stand-alone mode refers to the way that

Description: Compile hadoop program using eclipse in window and run on hadoop. the following error occurs: 11/10/28 16:05:53 info mapred. jobclient: running job: job_201110281103_000311/10/28 16:05:54 info mapred. jobclient: Map 0% reduce 0%11/10/28 16:06:05 info mapred. jobclient: task id: attempt_201110281103_0003_m_000002_0, status: FailedOrg. apache. hadoop.

Hadoop interview questions (1) and hadoop interview questions I. Q : 1. Briefly describe how to install and configure an apache open-source version of hadoop. You only need to describe it. You do not need to list the complete steps and the steps are better. 1) install JDK and configure environment variables (/etc/profile) 2) disable the Firewall 3) configure the

Today the Hadoop authoritative Guide Weather Data sample code runs through the Hadoop cluster and records it. Before the Baidu/google how also did not find how to map-reduce way to run in the cluster every step of the specific description, after a painful headless fly-style groping, success, a good mood ... 1 Preparing the Weather forecast data (simplified version of the data on the authoritative guide 5-9

in ~/.ssh/: Id_rsa and id_rsa.pub; These two pairs appear, similar to keys and locks.Append the id_rsa.pub to the authorization key (there is no Authorized_keys file at this moment)$ cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys(3) Verify that SSH is installed successfullyEnter SSH localhost. If the display of a native login succeeds, the installation is successful.3. Close the firewall $sudo UFW disableNote: This step is very important, if you do not close, there will be no problem finding D

As you know, Namenode has a single point of failure in the Hadoop system, which has been a weakness for high-availability Hadoop. This article discusses several solution that exist to solve this problem. 1. Secondary NameNode principle: secondary NN periodically reads the editlog from the NN, merging with the image that it stores to form a new metadata image advantage: The earlier version of

The two test VMS are rehl 5.3x64. The latest JDK version is installed and SSH password-free logon is correctly set.Server 1: 192.168.56.101 dev1Server 2: 192.168.56.102 dev2Slave. Log on to dev1 and run the following command:# Cd/usr/software/hadoop# Tar zxvf hadoop-0.20.1.tar.gz# Cp-A hadoop-0.20.1/usr/hadoop# Cd/usr/

Hadoop Rack-aware1. BackgroundHadoop is designed to take into account the security and efficiency of data, data files by default in HDFs storage three copies, the storage policy is a local copy,A copy of one of the other nodes in the same rack, a node on a different rack.This way, if the local data is corrupted, the node can get the data from neighboring nodes in the same rack, the speed is certainly faster than the data from the cross-rack node;At th

EnvironmentWindows 7 x64 bit, Visual Studio ProfessionalHadoop Source Version 2.2.0Step (from the book "Pro Apache Hadoop, Second Edition" slightly modified. Ensure that JDK, 1.6 is, or higher is installed. We assume that it's installed in thec:/myapps/jdkl6/ folder, which should has a bin subfolder. Download the hadoop-2.2.x-src.tar.gz files (2.2.0 at the time of this writing) from the Download sect