java and hadoop

1. Cloudera IntroductionHadoop is an open source project that Cloudera Hadoop, simplifies the installation process, and provides some encapsulation of Hadoop.Depending on the needs of the Hadoop cluster to install a lot of components, one installation is more difficult to configure, but also consider ha, monitoring and so on.With Cloudera, you can easily deploy clusters, install the components you need, and

Inkfish original, do not reprint commercial nature, reproduced please indicate the source (http://blog.csdn.net/inkfish). Hadoop is an open source cloud computing platform project under the Apache Foundation. Currently the latest version is Hadoop 0.20.1. The following is a blueprint for Hadoop 0.20.1, which describes how to install

login (Hadoop user) 1. Generate Key Ssh-keygen-t DSA (and then always press ENTER) automatically generates an. ssh folder with two files in it 2. Generate Authorized_keys Enter/home/hadoop/.ssh Directory Cat Id_dsa.pub >> Authorized_keys 3. Granting executive authority to Authorized_keys chmod Authorized_keys 4. Test if you can log on locally without a password SSH localhost If you do not need

Inkfish original, do not reprint commercial nature, reproduced please indicate the source (http://blog.csdn.net/inkfish). Hadoop is an open source cloud computing platform project under the Apache Foundation. Currently the latest version is Hadoop 0.20.1. The following is a blueprint for Hadoop 0.20.1, which describes how to install

Currently in Hadoop used more than lzo,gzip,snappy,bzip2 these 4 kinds of compression format, the author based on practical experience to introduce the advantages and disadvantages of these 4 compression formats and application scenarios, so that we in practice according to the actual situation to choose different compression format. 1 gzip compression Advantages: The compression ratio is high, and the compression/decompression speed is relatively fas

, ItemCF, SlopeOne) Distributed Recommenders ItemCF Vector similarity calculation RowSimilarityJob Calculate similarity between columns VectorDistanceJob Calculate the distance between vectors Non-Map-Reduce Algorithm Hidden Markov Models Hidden Markov Model Set Method Extension Collections Added java Collections classes. Ii. Mahout installation and configuration 1. Download

means you need to install the Java JDK and configure the Java_home The components of 5.hadoop are configured through XML. After you download a good Hadoop on the official web, unzip and modify the corresponding configuration file in the/etc/hadoop directory 工欲善其事, its prerequisite. Here's what you can say about the

Preparatory work: 1, install the Hadoop; 2. Create a Helloworld.jar package, this article creates a jar package under the Linux shell: Writing Helloworld.java filespublic class HelloWorld{public static void Main (String []args) throws Exception{System.out.println ("Hello World");} } Javac Helloworld.java is compiled and gets Helloworld.classIn the catalogue CV MANIFEST.MF file:manifest-version:1.0CREATED-BY:JDK1.6.0_45 (Sun Microsystems Inc.)Main-cl

to hadoop user $ mkdir ~ /. Ssh $ chmod 700 ~ /. Ssh $ cat ~ /Id_rsa.pub> ~ /. Ssh/authorized_keys -- append to the authorization file "authorized_keys" $ chmod 600 ~ /. Ssh/authorized_keys -- modify permission $ su -- switch back to root user # vim/etc/ssh/sshd_config -- modify ssh configuration file RSAAuthentication yes # enable RSA Authentication PubkeyAuthentication yes # enable public key private key pair authentication Method AuthorizedKeysFil

checksum ready command was run using/root/APP/hadoop/share/hadoop/common/hadoop-common-2.6.0-cdh5.7.0.jar [[email protected] hadoop] # You can see the above output result, it means there is no problem. If you are not at ease, check yarn. [[Email protected] hadoop] # yarn ve

Recent Big Data Compare fire, so also want to learn a bit, so install Ubuntu Server on the virtual machine, then install Hadoop. Here are the installation steps:1. Installing JavaIf it is a new machine, the default is not to install Java, run java–version named to see if you can view the Java version, if

. Ssh/id_rsa.pub Hadoop@*.*.*.*:/home/hadoop/id_rsa.pub Cat ~/id_rsa.pub >> ~/.ssh/authorized_keys Test Login: SSH localhost or ssh *.*.*.* K) Compiling I. Download to the official website, I will not write Ii. we've installed Hadoop in/usr/local/. Tar zxvf hadoop-0.20.2.tar.gz Ln-s

there is no tab in a row of data, the entire row of data is null as the Key,value value. However, these can also be customized for processing. when reducer is defined as an executable, each reducer task initialization starts the process independently. When the reducertask runs, the input key-value data is converted into rows of data as input to reducer. At the same time, reducer collects row data and converts the row data into Key-value form output. By default, the data in front of the first t

special symbols will cause startup problems. Modify the/etc/hosts of the machine and add the ing between IP address and hostname. 2). Download and decompress the stable version of hadoop package and configure the Java environment (for Java environment, generally ~ /. Bash_profile, considering Machine security issues ); 3). No key. Here is a small trick: On hadoo

/ In the Libexec directory, there are several lines of script in the hadoop-config.sh filehadoop-config.sh The code is as follows Copy Code If [F "${hadoop_conf_dir}/hadoop-env.sh"]; Then. "${hadoop_conf_dir}/hadoop-env.sh"Fi Test $hadoop_home/conf/hadoop-env.sh as plain file afte