hadoop in nutshell

1. Concept2. ReferencesImprove the MapReduce job Efficiency Note II of Hadoop (use combiner as much as possible): Http://sishuo (k). com/forum/blogpost/list/5829.htmlHadoop Learning notes -8.combiner and custom Combiner:http://www.tuicool.com/articles/qazujavHadoop in-depth learning: combiner:http://blog.csdn.net/cnbird2008/article/details/23788233(mean Scene) 0Hadoop using combiner to improve Map/reduce program efficiency: http://blog.csdn.net/jokes0

from the Agent cannot be received.请确保主机的名称已正确配置。请确保端口 7182 可在 Cloudera Manager Server 上访问（检查防火墙规则）。请确保正在添加的主机上的端口 9000 和 9001 空闲。检查正在添加的主机上 /var/log/cloudera-scm-agent/ 中的代理日志（某些日志可在安装详细信息中找到）。Could not find config file/var/run/cloudera-scm-agent/supervisor/supervisord.confThe solution to this error is:After we have modified our/etc/hosts file, we have to restart the service cloudera-scm-agentService Cloudera-scm-agent Restart8. Cannot be displayed after installing cm9, 7180 interface cannot op

Overview: The file system (FS) shell contains commands for various classes of-shell, directly interacting with Hadoop Distributed File System (HDFS), and support for other file systems, such as: Local file system fs,hftp Fs,s3 FS, and others. Calls to the FS shell: Bin/hadoop FS All FS shell commands have URI paths as parameters, and the URI forma

Notes on Hadoop single-node pseudo-distribution Installation Lab EnvironmentCentOS 6.XHadoop 2.6.0JDK 1.8.0 _ 65 PurposeThe purpose of this document is to help you quickly install and use Hadoop on a single machine so that you can understand the Hadoop Distributed File System (HDFS) and Map-Reduce framework, for example, run the sample program or simple job on H

1 Hadoop configurationcaveats: Turn off all firewalls server ip system master centos 6.0 X64 slave1 10.0.0.11 Centos 6.0 X64 slave2 10.0.0.12 centos 6.0 X64 Hadoop version: hadoop-0.20.2.tar.gz1.1 in master: (Operations

Hadoop is a distributed filesystem (Hadoop distributedfile system) HDFS. Hadoop is a large amount of data that can beDistributed Processingof theSoftwareFramework. Hadoop processes data in a reliable, efficient, and scalable way. Hadoop is reliable because it assumes that

Root @ scutshuxue-desktop:/home/root/hadoop-0.19.2 # bin/hadoop FS-put conf input10/07/18 12:31:05 info HDFS. dfsclient: Org. apache. hadoop. IPC. remoteException: Java. io. ioexception: File/user/root/input/log4j. properties cocould only be replicated to 0 nodes, instead of 1At org. Apache. hadoop. HDFS. server. namen

Setting up Hadoop cluster environment steps under Ubuntu 12.04I. Preparation before setting up the environment:My native Ubuntu 12.04 32bit as Maser, is the same machine that was used in the stand-alone version of the Hadoop environment, http://www.linuxidc.com/Linux/2013-01/78112.htmAlso in the KVM Virtual 4 machines, respectively named:Son-1 (Ubuntu 12.04 32bit),Son-2 (Ubuntu 12.04 32bit),Son-3 (CentOS 6.

the RM with several HA-related options and switches the Active/standby mode. The HA command takes the RM service ID set by the Yarn.resourcemanager.ha.rm-ids property as the parameter.$ yarn rmadmin-getservicestate rm1 Active $ yarn rmadmin-getservicestate RM2 StandbyIf automatic recovery is enabled, then you can switch commands without having to manually.$ yarn Rmadmin-transitiontostandby rm1 Automatic failover is enabled for [email protected] refusing to manually manage HA State, since it cou

-generated Method StubFile docdirectory=NewFile (Docdirectorypath); if(!docdirectory.isdirectory ()) {System.out. println ("Provide an absolute path of a directory that contains the documents to be added to the sequence file"); return; } /** Sequencefile.writer sequencefilewriter = * Sequencefile.createwriter (FS, Conf, new Path (Sequencefil Epath), * text.class, Byteswritable.class); */org.apache.hadoop.io.SequenceFile.Writer.Option FilePath=sequencefile.writer. File (NewPath (Se

insideLet's modify the hostTwo comments out of the front.6. Configure the Yum source6.1 Copying filesDelete the repo file that comes with the system in the/ETC/YUM.REPOS.D directory firstWill: Create a new file: Cloudera-manager.repoTouch Cloudera-manager.repoThe contents of the file are:BaseURL back is the folder inside your var/www/html.baseurl=http://Correct the second time you do itThird Amendment[Cloudera-manager]Name=cloudera ManagerBaseURL = Http://192.168.42.99/cdh/cm5.3/packageGpgcheck

.el6.noarch.rpm/download/# Createrepo.When installing Createrepo here is unsuccessful, we put the front in Yum.repo. Delete something to restoreUseyum-y Installcreaterepo Installation TestFailedAnd then we're on the DVD. It says three copies of the installed files to the virtual machine.Install deltarpm-3.5-0.5.20090913git.el6.x86_64.rpm FirstError:Download the appropriate rpmhttp://pkgs.org/centos-7/centos-x86_64/zlib-1.2.7-13.el7.i686.rpm/download/Http://pkgs.org/centos-7/centos-x86_64/glibc-2

I was fortunate enough to take the MOOC college Hadoop experience class at the academy. This is the little Elephant College hadoop2. X Overview Notes for chapter eighthThe main introduction is HBase, a distributed database application case.Case Overview:1) Time series database (OPENTSDB) Use HBase to store time series data, every moment is resolved, the database is open source 2) hbase Crawler Scheduler Library Vertical Search Crawler Mass crawler (wh

Hadoop is a project under Apache. It consists of HDFS, mapreduce, hbase, hive, Zookeeper, and other Members. HDFS and mapreduce are two of the most basic and important members. HDFS is an open-source version of Google gfs. It is a highly fault-tolerant distributed file system that provides high-throughput data access and is suitable for storing massive (Pb-level) data) (usually more than 64 MB), the principle is as follows: The Master/Slave struct

;padding:0px;border:0px;background-image: none; "/> 1. The principles have been described in the diagram, not another large paragraph of text explained, 2. In the above two diagrams, except for the "actual business object class", all belong to the structure or frame part; 3. If you use OO thinking to review the above two charts, you will be complaining about the bad design, here just to describe the work of the distributed system as simple as possible, you can use the policy mode to ada

FS ShellThe call file system (FS) shell command should use the form Bin/hadoop FS scheme://authority/path. For the HDFs file system, Scheme is HDFs, to the local file system, scheme is file. The scheme and authority parameters are optional, and if not specified, the default scheme specified in the configuration is used. An HDFs file or directory such as /parent/child can be represented as Hdfs://namenode:namenodeport/parent/child, or simpler /parent/

Read file:is the process by which HDFs reads files:Here is a detailed explanation:1. When the client begins to read a file, the client first obtains the Datanode information for the first few blocks of the file from Namenode. (steps)2. Start calling read (), the Read () method, first to read the first time from the Namenode to obtain a few blocks, when the read is completed, then go to Namenode take a block of datanode information. (Step 3,4,5)3. Call the Close method to complete the read. (Step

[Hadoop] 5. cloudera manager (3) and hadoopcloudera installed on HadoopInstall Http://blog.sina.com.cn/s/blog_75262f0b0101aeuo.html Before that, install all the files in the cm package This is because CM depends on postgresql and requires postgresql to be installed on the local machine. If it is installed online, it is automatically installed in Yum mode. Because it is offline, postgresql cannot be installed automatically. Check whether postgresql

1. By default, the Yarn log only displays info and above level information, and it is necessary to display the necessary debug information when the system is developed two times. 2. Configure yarn to print debug information to the log file, just modify its startup script sbin/yarn-daemon.sh, and change the info to debug (this step only). Export Yarn_root_logger=${yarn_root_logger:-debug,rfa} 3. For HDFs, the modification method is similar, only need to modify the sbin/

Original articles, reproduced please mark from http://blog.csdn.net/lsttoy/article/details/53406840.First, go to Apache to see the official support version You can see that hadoop2.4.x later versions basically support hbase1.2.4.The installation starts next. The first step is to download the latest version from the Apache Foundation Https://mirrors.tuna.tsinghua.edu.cn/apache/hbase/1.2.4/hbase-1.2.4-bin.tar.gz If you can not go to csdn and other major sites to download. Step two , unzip to the