commands:
$ Start-all.sh
In fact, this script calls the above two commands.
The local computer starts three Daemon Processes: One namenode, one secondary namenode, and one datanode. You can view the log files in the logs directory to check whether the daemon is successfully started, or view jobtracker at http: // localhost: 50030/or at http: // localhost: 50070/view namenode. In addition, the JPS command of Java can also check whether the daemon is running:
$ JPs
6129 SecondaryNameNode6262 Job
This document describes how to operate a hadoop file system through experiments.
Complete release directory of "cloud computing distributed Big Data hadoop hands-on"
Cloud computing distributed Big Data practical technology hadoop exchange group:312494188Cloud computing practices will be released in the group every day. welcome to join us!
First, let's loo
cannot start yarn on the namenode, yarn should be started on the machine where the Resoucemanager is located.4. Test the MapReduce programFirst create a directory to hold the input data command: Bin/hdfs dfs-mkdir-p/user/beifeng/mapreduce/wordcount/input Upload file to File system command: Bin/hdfs dfs-put/opt/modules/hadoop-2.5.0/wc.input/user/beifeng/mapreduce/
Content
Note
Next day
1th topic: Thorough Mastery of MapReduce(from a code perspective to analyze the specific process of mapreduce execution and the ability to develop MapReduce code)1. The classic steps of MapReduce execution2, wordcount operation Process Analysis3, mapper and reducer analysis4. Custom writable5, the difference between the old and new APIs and how to use the API6. Package the MapReduce program into a jar
warranties or CONDITIONS of any KIND, either express or implied.# see the License forThe specific language governing permissions and# limitations under the license.# Start all Hadoop daemons. Run this on master node.Echo "This script is Deprecated. Instead use start-dfs.sh and start-yarn.sh" #这里说明了这个脚本已经被弃用了, we need to start with start-dfs.sh and start-yarn.sh. bin = ' #真正执行的是以下两个, that is, the execution of start-dfs.sh and start-yarn.sh two s
.
WordCount
One: Official website example
WordCount is a sample of Hadoop's official website, packaged in Hadoop-mapreduce-examples-
Address of the 2.7.1 version: Http://hadoop.apache.org/docs/r2.7.1/hadoop-mapreduce-client/hadoop-mapreduce-client-core/ Map
Content
Note
Next day
1th topic: Thorough Mastery of MapReduce(from a code perspective to analyze the specific process of mapreduce execution and the ability to develop MapReduce code)1. The classic steps of MapReduce execution2, wordcount operation Process Analysis3, mapper and reducer analysis4. Custom writable5, the difference between the old and new APIs and how to use the API6. Package the MapReduce program into a jar
Objective: to use eclipse on the local machine (Win7) to operate Hadoop on the virtual machine (redhat) for learning and experiment purposes. general workflow-Hadoop installation section: 1. implement ssh password-less authentication configuration in linux 2. install jdk in linux and configure environment variables
Objective: to use eclipse on the local machine (Win7) to operate
details online.8. Run the wordcount routine provided by hadoop.Step 1: Doop @ master :~ /Hadoop-0.20.205.0/bin/$ hadoop namenode-format// Format the file system and create a new file system.Step 2: Doop @ master :~ /Hadoop-0.20.205.0/bin $ start-all.sh// Start all the daemon processes of hadoop.Step 4: Doop @ master :
configuration is correct, check the configuration if you see "Deny Connection".4.3 First map/reduce ProjectCreate a new Map/reduce project and copy the Wordcount.java in example to the new project. First write a data input file, as follows:Create the/tmp/workcount directory on HDFs with the command of Hadoop, with the following command:Hadoop Fs-mkdir/tmp/wordcountCopy the newly created Word.txt to HDFs with the copyfromlocal command as follows:Hadoo
that you configure in Mapred-site.xml, Core-site.xml, respectively. Such as:
4. New project.File-->new-->other-->map/reduceproject, the project name can be arbitrarily taken, such as WordCount.Copy the Hadoop installation directory/src/example/org/apache/hadoop/examples/wordcount.java to the newly created project WordCount, delete Wordcount.java first row pack
Solve Exception: org. apache. hadoop. io. nativeio. NativeIO $ Windows. access0 (Ljava/lang/String; I) Z and other issues, ljavalangstring
I. Introduction
Windows Eclipse debugging Hadoop2 code, so we in windows Eclipse configuration hadoop-eclipse-plugin-2.6.0.jar plug-in, and when running Hadoop code appeared a series of problems, after several days, the code c
you can see it) here most of the attributes have been automatically filled in, in fact, is the core-defaulte.xml, hdfs-defaulte.xml, mapred-defaulte.xml inside some of the configuration properties shown. When installing hadoop, the configuration files of its site series are changed, so the same settings should be made here. The main concern is the following attributes: fs. defualt. name: mapred has been set on the General tab. job. tracker: dfs is al
line around to the position of #export java_home=******* so to the typeface, first will # (here # for comment to effect) remove, modify Java_ The value of home is the JDK in your machine to the file path, where the value and/etc/profile are the same. You can now run a Hadoop program in stand-alone mode, determining that the current path is a Hadoop folderBin/hadoop
port configured in Mapred-site.xml, typically 9001, the default is 504003) "DFS Master": This corresponds to the port of HDFs, corresponding to the Core-site.xmlA) Host: The IP of the HDFs with Hadoop, which is localhost, this cannot be changedB) port: Port corresponding to HDFs, port configured in Mapred-site.xml, typically 9000, default is 50400Note: There is also a user name below, the default root I did not change.Note: Open perspective, on the r
The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion;
products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the
content of the page makes you feel confusing, please write us an email, we will handle the problem
within 5 days after receiving your email.
If you find any instances of plagiarism from the community, please send an email to:
info-contact@alibabacloud.com
and provide relevant evidence. A staff member will contact you within 5 working days.