bin/hadoop jar share/hadoop/mapreduce/hadoop-mapreduce-examples-2.6.4.jar wordcount /WordCount/WordCount /WCOutput 输出文件不能实现存在,比如说/WordCount这样是不行的 虽然他是第一级文件夹 但是已存在了,不可用 原来提示我,日志冲突,我美观,我以为是不是hadoop native造成的,后来吧多余的mahout的jar删了,里面也有slf4j,然后竟然运行成功了额,虽然也不…

1. MapReduce使用 MapReduce是Hadoop中的分布式运算编程框架,只要按照其编程规范,只需要编写少量的业务逻辑代码即可实现 一个强大的海量数据并发处理程序 2. 运行Hadoop自带的MapReduce程序(word count单词统计功能) 1.在HDFS中创建层级目录,并且上传文件到指定目录:hadoop fs -mkdir -p /wordcount/input 2.上传文件到HDFS指定目录:hadoop fs -put a.txt  b.txt  /wordcoun…

启动eclipse:打开windows->open perspective->other->map/reduce 可以看到map/reduce开发视图.设置Hadoop location. 打开windows->show view->other-> map/reduce Locations视图,在点击大象后[new Hadoop location]弹出的对话框(General tab)进行参数的添加: Location name: 任意 map/reduce maste…

运行hadoop2 自带的圆周率计算方法时,报错,找了半天,原来是在配置hadoop临时目录时,没有给权限,找到配置的hadoop临时目录文件夹,修改权限即可 Application application_1548242073562_0005 failed 2 times due to AM Container for appattempt_1548242073562_0005_000002 exited with exitCode: 1 Failing this attempt.Diagno…

1.准备文件 [root@master ~]# cat input.txt hello java hello python hello c hello java hello js hello html hello java [root@master ~]# hadoop fs -mkdir /input [root@master ~]# hadoop fs -put input.txt /input [root@master ~]# hadoop fs -ls /input Found 1 it…

在hadoop2.9.0版本中,对namenode.yarn做了ha,随后在某一台namenode节点上运行自带的wordcount程序出现偶发性的错误(有时成功,有时失败),错误信息如下: // :: INFO client.ConfiguredRMFailoverProxyProvider: Failing over to rm2 // :: INFO input.FileInputFormat: Total input files to process : // :: INFO mapre…

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以往都是用java运行spark的没问题,今天用scala在eclipse上运行spark的代码倒是出现了错误 ,记录 首先是当我把相关的包导入好后,Run,报错: Exception in thread "main" org.apache.spark.SparkException: A master URL must be set in your configuration at org.apache.spark.SparkContext.<init>(SparkCont…

1.启动所有的线程服务 start-all.sh 记得要查看线程是否启动 jps 2.在根目录创建 wordcount.txt 文件 放置一些数据 3.创建  hdfs dfs -mkdir /文件夹名称 创建成功 4.将wordcount.txt文件放置 hadfs01下 放置成功 5.到如下图所示的路径 5.1 5.2 执行该命令 hadoop jar hadoop-mapreduce-examples-2.6.5.jar wordcount /hdfs01/wordcount.txt /w…

1.在hadoop所在目录“usr/local”下创建一个文件夹input root@ubuntu:/usr/local# mkdir input 2.在文件夹input中创建两个文本文件file1.txt和file2.txt,file1.txt中内容是“hello word”,file2.txt中内容是“hello hadoop”.“hello mapreduce”(分两行). root@ubuntu:/usr/local# cd inputroot@ubuntu:/usr/local/inp…