hadoop cluster tutorial

Address: http://blog.cloudera.com/blog/2013/04/how-to-use-vagrant-to-set-up-a-virtual-hadoop-cluster/ Vagrant is a very useful tool that can be used to program and manage multiple virtual machines (VMS) on a single physical machine ). It supports native virtualbox and provides plug-ins for VMWare Fusion and Amazon EC2 Virtual Machine clusters. Vagrant provides an easy-to-use ruby-based internal DSL that all

Yesterday because Datanode appeared large-scale offline situation, the preliminary judgment is dfs.datanode.max.transfer.threads parameter set too small. the hdfs-site.xml configuration files for all Datanode nodes are then adjusted. After restarting the cluster, in order to verify, try to run a job, see the configuration of the job in Jobhistory, it is surprising that the display is still the old value, that is, the job is still running with the old

Hadoop advanced 1. Configure SSH-free (1) Modify the slaves fileSwitch to master machine, this section is all done in master.Enter the/usr/hadoop/etc/hadoop directory, locate the slaves file, and modify:slave1slave2slave3(2) Sending the public keyEnter the. SSH directory under the root directory: Generate Public Private key SSH-KEYGEN-T RSA

Hadoop generation cluster running code case Cluster a master, two slave,ip are 192.168.1.2, 192.168.1.3, 192.168.1.4 Hadoop version is 1.2.1 First, start Hadoop go to the bin directory of Hadoop second, the establishment of data

-15 11:10 /user/hadoop/wordcount/output/_logs-rw-r--r-- 1 hadoop supergroup 41 2014-09-15 11:11 /user/hadoop/wordcount/output/part-r-00000使用 hadoop fs –cat wordcount/output/part-r-00000命令查看输出结果，如下所示：#查看结果输出文件内容[[emailprotected] WordCount]$ hadoop fs -cat wordcount/output/p

Hadoop cluster itself is not recommended to store small files, because in the MapReduce program scheduling process, the default map input is not cross-file, if a file is small (much smaller than the size of a block, the current cluster block size is 256M), the scheduling will also generate a map, and a map only processes this small file, so that the MapReduce pro

Overview: Hadoop cluster, 1 sets of Namenode, a secondnamenode, a jobtracker and Taiwan Datanode, the specific installation method on the Internet there are too many, the following is just their own set up the experimental environment and the problem solution. 1, the configuration IP corresponding hostname/etc/hosts configuration namenode and Datanode, shape as follows: 192.168.1.1 Namenode 192.168.1.2 Seco

Section 131 :Hadoop Cluster management tool equalizer Balancer The actual combat detailed study notesWhy do I need a equalizer?As the cluster runs, the block on each data storage node in HDFs may be distributed more and more unevenly, resulting in reduced MapReduce locality when running the job . One of the essence of distributed computing: data does not move cod

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First run MapReduce, recorded several problems encountered, Hadoop cluster is CDH version, but my Windows local jar package is directly with hadoop2.6.0 version, and did not specifically look for CDH version of the1.Exception in thread "main" Java.lang.NullPointerException Atjava.lang.ProcessBuilder.startDownload Hadoop2 above version, in the Hadoop2 bin directory without Winutils.exe and Hadoop.dll, find t

Add hard disks to the Hadoop cluster. Hadoop worker nodes expand hard disk space After receiving the task from the boss, the hard disk space in the Hadoop cluster is insufficient, and a machine is required to be added to the Hadoop