OverviewAlthough it is now said that the Big memory era, but the development of memory can not keep up with the pace of data it. So we're going to try to reduce the amount of data. The reduction here is not really a reduction in the amount of data, but rather a dispersion of data. stored separately, calculated separately. This is the core of MapReduce distributed.Copyright noticeCopyright belongs to the author.Commercial reprint please contact the author for authorization, non-commercial reprint
that corresponds to the IP of your system configurationConfigure Mapred-site.xmlSo the configuration is complete.Open the virtual machine, turn on the yarn service, enter JPS to see if there are two parts of ResourceManager NodeManager. There is a successful configuration.Running WordCount algorithm under virtual machineEnter the wordcount algorithm in hadoop-->
Record Spark's WordCount applet: premise: HDFs is already open
Create a file named Wc.input and upload it to HDFs./user/hadoop/spark/, content such as[Email protected] hadoop-2.6.0-cdh5.4.0]# Bin/hdfs dfs-put wc.input/user/hadoop/spark/ Upload[Email protected] hadoop-2.6.0
I don't know why I don't really want to learn about mapreduce, but now I think this may take some time to study. Here I will record the wordcount code of the next mapreduce instance.
1,
Pom. xml:
2、WordCountMapper:
Import org. Apache. hadoop. Io. i
Create the file folder under/home/yuanqin/, and then set up File1.txt, File2.txt, file3.txt in the folderFile1 content: Hello WordFile2 content: Hello HadoopFile3 content: Hello, who are you? Hi, I'm qin.Enter in the Hadoop directory: Bin/hadoop fs-mkdir inputBin/hadoop Fs-put/home/yuanqin/file/file*.txt InputBin/hadoop
WordCount is the most commonly used example of distributed computing, such as Hadoop, storm,iveely computing, and so on. Understand the WordCount on the iveely computing on the operating principle, it is easy to write a new distributed program. I already know how to deploy iveely computing and submit tasks in the previous article, and now we'll dive into
,current_count)3. Modify its authority accordinglychmod a+x/home/hadoop/wc/mapper.pychmod a+x/home/hadoop/wc/reducer.py4. Test run code on this machine5. View running Results2. Using MapReduce to process meteorological data setsWrite a program to find the highest minimum temperature per day with the highest minimum temperature
The meteorological data set is: FTP://FTP.NCDC.NOAA.GOV/PUB/DATA/NOAA
Eclipse Run WordCount StepsThe first step: Build the project and import the code.Step Two: Create a file to write the data (separated by a space) and upload it to HDFs.1. Create the file and write the data:2. Uploading HDFsOn the line under Hadoop permissions:Command: Hadoop fs-put new file path input directorysuch as: Hadoop
Spark is a distributed memory computing framework that can be deployed in yarn or Mesos managed distributed Systems (Fully distributed) or in a pseudo distributed way on a single machine. It can also be deployed on a single machine in a standalone manner. There are interactive and submit ways to run spark. All of the actions in this article are interactive operations that are deployed in standalone mode by Spark. Refer to Hadoop Ecosystem for specific
Writing WordCount program tasks in Python
Program
WordCount
Input
A text file that contains a large number of words
Output
Each word in the file and the number of occurrences (frequency), sorted alphabetically by word, with each word and its frequency as a line, with intervals between words and frequencies
Write the map function, r
Ide:eclipsespark:spark-1.1.0-bin-hadoop2.4scala:2.10.4To create a Scala project, write the WordCount program as followsPackage Com.luogankun.spark.baseImportorg.apache.spark.SparkConfImportOrg.apache.spark.SparkContextImportorg.apache.spark.sparkcontext._/** *Count character Occurrences*/Object Workcount {defMain (args:array[string]) {if(Args.length ) {System.err.println ("Usage: ") System.exit (1)} Val conf=New sparkconf () Val SC=new Sparkcontext (c
Running HadoopEnter the bin directory of the installation directory for Hadoop and format the file system with the-format command.$Hadoop Namenode-formatNote: To avoid Namenode namespace ID and Datanode namespace ID when you perform the format-format commandThe inconsistency. This is because each format generates temporary file record information, such as name, Data, temp,Multiple formatting results in a lo
First, enter the IDE interfaceCD ~/downloads/idea/binidea.shIi. Building a Scala projectStep 1 : Import spark-hadoop corresponding package, select "File" –> "Project Structure" –> "Libraries", select "+" to import Spark-hadoop corresponding package:Click "OK" to confirm:Click "OK":When idea is done, we'll find that Spark's jar package is imported into our project:Step two, write Scala code implementation wo
is actually showing some of the configuration properties in the core XML configuration files.
After the configuration is complete, return to eclipse, we can see that under Map/reduce locations there will be more than one hadoop-master connection, this is the newly created map/reduce named Hadoop-master Location connection, as shown in:2.3 View HDFs(1) The file structure in HDFs is shown by selecting t
not a number, just ignore it . Continue ifCurrent_word = =Word:current_count+=CountElse: ifCurrent_word:Print "%s\t%s"%(Current_word, current_count) Current_count=Count Current_word=WordifWord = = Current_word:#Don't forget the final output Print "%s\t%s"% (Current_word, Current_count)The file reads the results of the mapper.py as input to the reducer.py and counts the total number of occurrences of each word, outputting the final result to stdout.Details: Split (' \ t ', 1)
Share today the steps to submit the Java-developed WordCount program to the spark cluster.Before the first step, upload the text file, Spark.txt, and then use the command Hadoop fs-put spark.txt/spark.txt. First: Look at the entire Code viewOpen the Wordcountcluster.java source file and modify the code here:Step Two:To make a good jar package, step right-click the project file----Runas--run configurationsFi
First, prepare the test data1, in the local Linux system/var/lib/hadoop-hdfs/file/path to prepare two files File1.txt and file2.txt, file list and their respective contents as shown:2. In HDFs, prepare the/input path and upload two files file1.txt and file2.txt as shown:Second, write the code, encapsulate the jar package and upload it to LinuxEncapsulate the code into Testmapreduce.jar and upload it to the Linux/usr/local path, as shown in:Third, run
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