hadoop namenode

program, and save the output in the Outputs folder#每次重新执行wordcount程序的时候, you need to delete the output folder first! Otherwise, it will go wrong$ bin/hadoop Jar Share/hadoop/mapreduce/sources/hadoop-mapreduce-examples-2.7.2-sources.jar Org.apache.hadoop.examples.WordCount Input Output4. View character Statistics results$ cat output/*VII. pseudo Distribution Mode

Chapter 2 mapreduce IntroductionAn ideal part size is usually the size of an HDFS block. The execution node of the map task and the storage node of the input data are the same node, and the hadoop performance is optimal (Data Locality optimization, avoid data transmission over the network ). Mapreduce Process summary: reads a row of data from a file, map function processing, Return key-value pairs; the system sorts the map results. If there are multi

second, Hadoop pseudo-distributed mode configuration The experiment needs to proceed after the previous stand-alone mode deployment 1. Configure Core-site.xml, Hdfs-site.xml,mapred-site.xml and Yarn-site.xml 1). Modify Core-site.xml: $ sudo gvim/usr/local/hadoop/etc/core-site.xml Common Configuration Item Description: Fs.default.name This is a URI that describes the

(Releaseversion), and set this featureMergeTo the main code line. Note that multiple branches may be developed at the same time,A branch with a higher version may be released before a branch with a lower version.. Because Apache usesFeature prevailsNew branches are extended, so before introducing the Apache hadoop version, we will first introduce several major features of the new version of Apache hadoop in

Hadoop is a distributed storage and computing platform for big data, distributed storage is HDFs (Hadoop distributed File System), and the compute platform is mapreduce. Hadoop is distributed storage data, data is transmitted over the network during storage, and bandwidth is limited, so if you use Hadoop at a small dat

Hadoop 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

[[emailprotected] usr]$ sudo tar –zxvf /home/hadoop/hadoop-1.2.1.tar.gz3) Renaming Hadoop[[emailprotected] usr]$ sudo mv hadoop-1.2.1/ hadoop/4) Assign the folder "Hadoop" Read permission to the

modify:/etc/hostname In addition, we need to make sure that the host name and IP address of each machine can be correctly resolved. A simple test method is to ping the host name, for example, Ping Frank-2 on Frank-1. If you can ping it, OK! If the hosts cannot be correctly parsed, you can modify the/etc/hosts file. If the hosts are used as namenode, you need to add the IP addresses of all hosts in the cluster and their corresponding host names in

) Configure Core-site.xml:vim Core-site.xml, add:Create the TMP folder under/usr/local/hadoop-2.4.1: mkdir tmp　　2) Configure Hdfs-site.xml:vim Hdfs-site.xml, add:Create a folder under/usr/local/hadoop-2.4.1: mkdir HDFs, mkdir hdfs/name, mkdir hdfs/data　　3) Configure Yarn-site.xml:vim Yarn-site.xml, add:　　4) configuration mapred-site.xml: CP mapred-site.xml.template Mapred-site.xml, vim mapred-site.xml , add

the amount of Io, can be made into a distributed cluster.Zookeeper is responsible for communication between server nodes and processes, which is a coordination tool, because almost every sub-project in Hadoop is made with an animal logo, so this coordinating software is called a zoo administrator.　　Hadoop architecture, two server cabinets, each of which represents a physical machine, each physical node con

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

; Property>Configuration>(5), Yarn-site.xmlVi/opt/hadoop/etc/hadoop/yarn-site.xmlConfiguration> Property> name>Yarn.resourcemanager.hostnamename> value>Node00value> Property> Property> name>Yarn.nodemanager.aux-servicesname> value>Mapreduce_shufflevalue> Property>Configuration>(6), SlavesNode01node023. Initialize HDFs/opt/