1. Create a userAddUser HDUserTo modify HDUser user rights:sudo vim/ect/sudoers, add HDUser all= (All:all) all in the file. 2. Install SSH and set up no password login1) sudo apt-get install Openssh-server2) Start service: SUDO/ETC/INIT.D/SSH start3) Check that the service is started correctly: Ps-e | grep ssh 4) Set password-free login, generate private key and public keySsh-keygen-t rsa-p ""Cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys 5) Password-free login: ssh localhost6) Exit3. Config
The first 2 blog test of Hadoop code when the use of this jar, then it is necessary to analyze the source code.
It is necessary to write a wordcount before analyzing the source code as follows
Package mytest;
Import java.io.IOException;
Import Java.util.StringTokenizer;
Import org.apache.hadoop.conf.Configuration;
Import Org.apache.hadoop.fs.Path;
Import org.apache.hadoop.io.IntWritable;
Import Org.apache.hadoop.io.Text;
Import Org.apache.hadoop.map
Because Hadoop is still in its early stage of rapid development, and it is open-source, its version has been very messy. Some of the main features of Hadoop include:
Append: Supports file appending. If you want to use HBase, you need this feature.
RAID: to ensure data reliability, you can introduce verification codes to reduce the number of data blocks. Link: https://issues.apache.org/jira/browse/HDFS/c
Write scalable, distributed data-intensive programs and basics
Understanding Hadoop and MapReduce
Write and run a basic MapReduce program
1. What is HadoopHadoop is an open-source framework for writing and running distributed applications to handle large-scale data.What makes Hadoop unique is the following points:
Convenient--hadoop run on a
Environment[Email protected] soft]#Cat/etc/Issuecentos Release6.5(Final) Kernel \ r \m[[email protected] soft]#uname-Alinux vm80282.6. +-431. el6.x86_64 #1SMP Fri Nov A Geneva: the: theUtc -x86_64 x86_64 x86_64 gnu/Linux[[email protected] soft]# Hadoop versionhadoop2.7.1Subversion https://git-wip-us.apache.org/repos/asf/hadoop.git-r 15ecc87ccf4a0228f35af08fc56de536e6ce657aCompiled by Jenkins on -- .-29t06:04zcompiled with Protoc2.5.0From source with c
1. The virtual machine installation hadoop,windows cannot access the Hadoop Web page http://master:50070/through the host name. Windows Ping Master also pings the method: Add Linux under Windows native C:\Windows\System32\drivers\etc\hosts files Hosts configure the hostname and IP address of the Hadoop machine to add in.
Issue 2, Windows Eclipse runni
Once Hadoop is installed, you will often be prompted with a warning:
WARN util. nativecodeloader:unable to load Native-hadoop library for your platform ...
Using Builtin-java classes where applicableSearched a lot of articles, all say is related to the system bit number, I use CentOS 6.5 64-bit operating system.
The first two days in the Docker image to find a step to solve the problem, the pro tried
VirtualBox build Pseudo-distributed mode: Hadoop Download and configurationAs a result of personal machine slightly slag, unable to deploy Xwindow environment, direct use of the shell to operate, want to use the mouse to click the operation of the left do not send ~1.hadoop Download and decompressionhttp://mirror.bit.edu.cn/apache/hadoop/common/stable2/
First, download the Hadoop websitehttp://hadoop.apache.orghttps://archive.apache.org/dist/hadoop/common/hadoop-2.6.0 Administrator Identity Decompression D:\Hadoop\hadoop-2.6.0Second, the download of winutilsAlso need to download Winutils.exe,requires a corresponding version
Part 1: hadoop BinThe following hadoop bin is based on the actual needs of the project:Hadoop ShellHadoop-config.sh, which is used to assign values to some variablesHadoop_home (hadoop installation directory ).Hadoop_conf_dir (hadoop configuration file directory ). Hadoop_slaves (-- the address of the file specified by
Ubuntu installation (Here I do not catch a map, just cite a URL, I believe that everyone's ability)Ubuntu Installation Reference Tutorial: http://jingyan.baidu.com/article/14bd256e0ca52ebb6d26129c.htmlNote the following points:1, set the virtual machine's IP, click the network connection icon in the bottom right corner of the virtual machine, select "Bridge mode", so as to assign to your LAN IP, this is very important because the back Hadoop to use th
Pre-Preparation 1. Create a Hadoop-related directory (easy to manage) 2, give Hadoop users and all group permissions to the/opt/* directorysudo chrown-r hadoop:hadoop/opt/*3, JDK installation and configuration configuration Hdfs/yarn/mamreduce1, decompression HadoopTAR-ZXF hadoop-2.5.0.tar.gz-c/opt/modules/(delete Doc's help document, save space) rm-rf/opt/module
-p '-F/HOME/U/.SSH/ID_DSASsh-keygen indicates that the key is generated-T means the specified generated key typeDSA is the meaning of DSA key authentication, that is, the key type-P provides a passphrase-f Specifies the generated key file(4) # cat/home/u/.ssh/id_dsa.pub >>/home/u/.ssh/authorized_keys# Add the public key to the public key file for authentication, Authorized_keys is the public key file for authentication(5) # Ssh-version# Verify that SSH installation is complete and the correct in
additional openssh-clients(3) # Mkdir-p ~/.ssh # Assume that after you install SSH, these folders are not actively generated by yourself, please create your own(4) # ssh-keygen-t Dsa-p "-F ~/.SSH/ID_DSASsh-keygen indicates that the key is generated-T means the specified generated key typeDSA is the meaning of DSA key authentication, that is, the key type-P provides a passphrase-f Specifies the generated key file(5) # cat ~/.ssh/id_dsa.pub >> ~/.ssh/authorized_keys# Add the public key to the pub
Knowing and learning about Hadoop, we have to understand the composition of Hadoop, and based on my own experience, I introduce the Hadoop component, the big data processing process, and the three aspects of Hadoop core:
Hadoop Components
650) this.width=650;
Compile the hadoop 2.x Hadoop-eclipse-plugin plug-in windows and use eclipsehadoopI. Introduction
Without the Eclipse plug-in tool after Hadoop2.x, we cannot debug the code on Eclipse. We need to package MapReduce of the written java code into a jar and then run it on Linux, therefore, it is inconvenient for us to debug the code. Therefore, we compile an Eclipse plug-in so that we can debug it locally. Afte
Full-text index-lucene,solr,nutch,hadoop LuceneFull-text index-lucene,solr,nutch,hadoop SOLRI was in last year, I want to lucene,solr,nutch and Hadoop a few things to give a detailed introduction, but because of the time of the relationship, I still only wrote two articles, respectively introduced the Lucene and SOLR, then did not write, but my heart is still loo
Today, HDFS, the core of hadoop, is very important. It is a distributed file system. Why does hadoop support massive data storage? In fact, it depends mainly on the HDFS capability, mainly on the ability of HDFS to store massive data.
1. Why can HDFS store massive data?
In the beginning, let's think about this problem. I don't need to talk about the basic concepts of HDFS ~ We focus on usage rather than "re
Tags: hadoop Linux environment construction
Build a pseudo-distributed hadoop Environment
1. network connection between the host machine (Windows) and the client (Linux installed in a virtual machine.
A) The host-only host is connected to the client separately;
Benefits: Network isolation;
Disadvantage: the virtual machine cannot communicate with other servers;
B. The bridge host is in the same LAN as the c
combine multiple files into one ZIP file. Each file is compressed separately, and all files are stored at the end of the ZIP file. This attribute indicates that the ZIP file supports splitting at the file boundary. Each part contains one or more files in the zip compressed file.
Hadoop CompressionAlgorithmAdvantages and disadvantages
When considering how to compress data that will be processed by mapreduce, it is important to consider whether the
The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion;
products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the
content of the page makes you feel confusing, please write us an email, we will handle the problem
within 5 days after receiving your email.
If you find any instances of plagiarism from the community, please send an email to:
info-contact@alibabacloud.com
and provide relevant evidence. A staff member will contact you within 5 working days.