hadoop fundamentals

For detailed steps, download the attachment: Install hadoop on Windows. The following are the main chapters: 1. Introduction This example describes how to install/start hadoop in windows. In this example, the following environment passes the test:★Operating System: Windows 7 Enterprise Edition (English version)★Hadoop: 0.20.2★Java JDK: 1.6.0.10★Eclipse: Helios★

下午对着源码看陆喜恒. Hadoop实战（第2版）6.4.1 （Shuffle和排序）Map端，发现与Hadoop 1.2.1的源码有些出入。下面作个简单的记录，方便起见，引用自书本的语句都用斜体表示。 依书本，从MapTask.java开始。这个类有多个内部类： 从书的描述可知，collect()并不在MapTask类，而在MapOutputBuffer类，其函数功能是 1、定义输出内存缓冲区为环形结构2、定义输出内存缓冲区内容到磁盘的操作 在collect函数中将缓冲区的内容写出时会调用sortAndSpill函数。好了，从这里开始就开始糊涂了，因为collect()没调用这个函数，接触Hadoop也就几天时间，啥都不懂，一下晕了。 简单表示下当前的函数调用关系： 0 ----MapOutputBuffer::co

Prepare the EnvironmentDownload Htrace-core-3.0.4.jar file FirstWebsite Link:http://mvnrepository.com/artifact/org.htrace/htrace-core/3.0.4Copy to the Share/hadoop/common/lib directory in HadoopAvoid errors where you cannot find a file.Download Hadoop2x-eclipse-pluginWebsite address:Https://github.com/winghc/hadoop2x-eclipse-pluginAfter decompression, upload to the server on HadoopIn/home/hadoop/hadoop2x-ec

Now that namenode and datanode1 are available, add the node datanode2 first step: Modify the Host Name of the node to be added hadoop @ datanode1 :~ $ Vimetchostnamedatanode2 Step 2: Modify the host file hadoop @ datanode1 :~ $ Vimetchosts192.168.8.4datanode2127.0.0.1localhost127.0 Now that namenode and datanode1 are available, add the node datanode2 first step: Modify the Host Name of the node to be added

1. Introduction:Import the source code to eclipse to easily read and modify the source.2. Description of the environment:MacMVN Tools (Apache Maven 3.3.3)3.hadoop (CDH5.4.2)1. Go to the Hadoop root and execute:MVN org.apache.maven.plugins:maven-eclipse-plugin:2.6: eclipse-ddownloadsources=true - Ddownloadjavadocs=truNote:If you do not specify the version number of Eclipse, you will get the following error,

Environment : Centos7+hadoop2.5.2+hive1.2.1+mysql5.6.22+indigo Service 2 train of thought : Hive load log →hadoop distributed execution → requirement data into MySQL Note : Hadoop log Analysis System on the Internet a lot of data, but most of them have to write a small problem, can not run smoothly, but this article has been personally validated, can be coherent. It also includes a detailed explanation of t

Generally, one machine in the cluster is specified as namenode, and another machine is specified as jobtracker. These machines areMasters. The remaining Machines serve as datanodeAlsoAs tasktracker. These machines areSlaves Official Address :(Http://hadoop.apache.org/common/docs/r0.19.2/cn/cluster_setup.html) 1 prerequisites Make sure that all required software is installed on each node of your cluster: Sun-JDK, ssh, hadoop Javatm 1.5.x mu

(1) First create Java projectSelect File->new->java Project on the Eclipse menu.and is named UploadFile.(2) Add the necessary Hadoop jar packagesRight-click the JRE System Library and select Configure build path under Build path.Then select Add External Jars. Add the jar package and all the jar packages under Lib to your extracted Hadoop source directory.All jar packages in the Lib directory.(3) Join the Up

This article has agreed:Dn:datanodeTt:tasktrackerNn:namenodeSnn:secondry NameNodeJt:jobtrackerThis article describes the communication protocol between the Hadoop nodes and the client.Hadoop communication is based on RPC, a detailed introduction to RPC you can refer to "Hadoop RPC mechanism introduce Avro into the Hadoop RPC mechanism"Communication between nodes

This article will go on to the wordcount example in the previous article to abstract the simplest process and explore how the System Scheduling works in the mapreduce operation process. Scenario 1: Separate data from operations Wordcount is the hadoop helloworld program. It counts the number of times each word appears. The process is as follows: Now I will describe this process in text. 1. The client submits a job and sends mapreduce programs and dat

platform 67. Hadoop-based large distributed data Warehouse fundamentals and application practices in the industry68. Spark-based real-time Data Warehouse cluster basics, and application practices in the industryIntroduction to 69.Hive Big Data Warehouse and application introductionAnalysis of platform architecture and core technology of 70.Hive Data Warehouse cluster71.Hive Server working principle an

After installing the Hadoop pseudo-distributed environment, executing the relevant commands (for example: Bin/hdfs dfs-ls) will appearWARN util. nativecodeloader:unable to load Native-hadoop library for your platform ... using Builtin-java classes where applicable, which is Because the installed Navtive packages and platforms do not match, the Hadoop source packa

Org. apache. hadoop. filecache-*, org. apache. hadoop I don't know why the package is empty. Should the package name be a class for managing File Cache? No information was found on the internet, and no answers were answered from various groups. Hope a Daniel can tell me the answer. Thank you. Why is there no hadoop-*-examplesjar file after the

Hadoop Learning Note 0003--reading data from a Hadoop URLfrom Hadoopurl reading Datato from Hadoop The simplest way to read files in a file system is to use the Java.net.URL object to open a data stream from which to read the data. The general format is as follows:InputStream in = null; try {in = new URL ("Hdfs://host/path"). OpenStream (); Process i

Preface Install the hadoop-2.2.0 64-bit version under Linux CentOS, solve two problems: first, resolve namenode cannot start, view log file logs/ Hadoop-root-namenode-itcast.out (your name is not the same as mine, see the Namenode log file on the line), which throws the following exception:Java.net.BindException:Problem binding to [xxx.xxx.xxx.xxx:9000] Java.net.BindException: Unable to specify the request