hadoop分布式安装

分布式安装(至少三台主机)：
环境所需软件：
CentOS7
hadoop-2.7.3.tar.gz
jdk-8u102-linux-x64.tar.gz

安装前准备工作：

1. 修改 /etc/hosts 文件
   vim /etc/hosts
   内容：
   192.168.10.11 bigdata1
   192.168.10.12 bigdata2
   192.168.10.13 bigdata3

2. 配置免密钥登陆
   cd
   ssh-keygen -t rsa
   一直回车，直到结束

                ssh-copy-id   .ssh/id_rsa.pub    bigdata1             ssh-copy-id   .ssh/id_rsa.pub    bigdata2             ssh-copy-id   .ssh/id_rsa.pub    bigdata3

3. 同步时间
   通过设置计划任务实现各主机间的时间同步
   vim /etc/crontab
   0 0 1 root ntpdate -s time.windows.com

               或者部署一个时间服务器实现同步，这里就不详细讲解了    （*）hdfs-site.xml                          dfs.replication          2                            core-site.xml                          fs.defaultFS          hdfs://bigdata1:9000                                   hadoop.tmp.dir          /root/training/hadoop-2.7.3/tmp             mapred-site.xml                          mapreduce.framework.name          yarn                 yarn-site.xml                          yarn.resourcemanager.hostname          bigdata1                                       yarn.nodemanager.aux-services          mapreduce_shuffle             对NameNode进行格式化: hdfs namenode -format                     日志：Storage directory /root/training/hadoop-2.7.3/tmp/dfs/name has been successfully formatted.    scp -r  /root/training/hadoop-2.7.3   bigdata2:/root/training/hadoop-2.7.3    scp -r  /root/training/hadoop-2.7.3   bigdata3:/root/training/hadoop-2.7.3    启动：start-all.sh = start-dfs.sh + start-yarn.sh                验证 （*）命令行：hdfs dfsadmin -report（*）网页：HDFS：http://192.168.157.12:50070/           Yarn：http://192.168.157.12:8088（*）Demo：测试MapReduce程序           example: /root/training/hadoop-2.7.3/share/hadoop/mapreduce/hadoop-mapreduce-examples-2.7.3.jar           hadoop jar hadoop-mapreduce-examples-2.7.3.jar wordcount /input/data.txt /output/wc1204