<mainClass>org.apache.hadoop.examples.ExampleDriver</mainClass> </manifest> </archive> </configuration> </plugin> 这决定了使用jar命令执行hadoop-mapreduce-examples-2.6.0.jar包时,实际执行了ExampleDriver的main方法,ExampleDriver的实现如下: public class ExampleDriver { public static void main(String ar...
dbcount: An example job that count the pageview counts from a database. distbbp: A map/reduce program that uses a BBP-type formula to compute exact bits of Pi. grep: A map/reduce program that counts the matches of a regex in the input. join: A job that effects a join over sorted...
MapReduce 单词计数应用程序示例包含在 HDInsight 群集中。 此示例位于群集默认存储的 /example/jars/hadoop-mapreduce-examples.jar 中。以下Java 代码是包含在 hadoop-mapreduce-examples.jar 文件中的 MapReduce 应用程序的源代码:Java 复制 package org.apache.hadoop.examples; import java.io.IOException; ...
cd hadoop-x.x.x/share/hadoop/mapreduce hadoop jar hadoop-mapreduce-examples-2.8.5.jar wordcount /expr/wordcount/data /expr/wordcount/output // 解释一下就是运行了example里的wordcount wordcount的输入在HDFS的/expr/wordcount/data中,输出结果在/expr/wordcount/output中(这个目录程序自动创建的 1. 2. ...
Hadoop计数器都是MapReduce程序中全局的计数器,跟MapReduce分布式运算没有关系,不是所谓的局部统计信息。 内置Counter Group包括:MapReduce任务计数器(Map-Reduce Framework)、文件系统计数器(File System Counters)、作业计数器(Job Counters)、输入文件任务计数器(File Input Format Counters)、输出文件计数器(File Outpu...
Sign in to download full-size image Fig. 4.MapReduce model. 1. Input reader: This reads data from files or databases and converts them into key/value pairs. The data sets are usually divided into splits, for example, the size of a split inHadoopdistributed file system (HDFS) is 64MB...
While Google introduced the first MapReduce framework, Apache Hadoop MapReduce is perhaps the most popular. MapReduce played a key role in advancing big data analytics, but it does have its drawbacks. For example, data is usually not retained in memory by MapReduce, and iterative logic is pos...
执行程序路径:单击“HDFS”,并选择待执行的jar文件。例如:hdfs://hacluster/tmp/hadoop-mapreduce-examples-xxx.jar(此处以hadoop example程序为例,已提前将jar包上传至HDFS) 执行程序参数:teragen 9999999 /tmp/teragen (表示随机生成9999999行的数据,并将执行结果放置在“/tmp/teragen”路径下) ...
yarn jar wordcountjava-1.0-SNAPSHOT.jar org.apache.hadoop.examples.WordCount /example/data/gutenberg/davinci.txt /example/data/wordcountout 此命令會啟動 WordCount MapReduce 應用程式。 輸入檔案為 /example/data/gutenberg/davinci.txt,輸出目錄則為 /example/data/wordcountout。 輸入檔和輸出都會...
use hadoop-examples.jar instead.# -JarFile = the JAR containing the MapReduce application# -ClassName = the class of the application# -Arguments = The input file, and the output directory$wordCountJobDefinition=New-AzHDInsightMapReduceJobDefinition`-JarFile"/example/jars/hadoop-mapreduce-examples...