1 /*
 2 @author :yinzhengjie
 3 Blog:http://www.cnblogs.com/yinzhengjie/tag/Hadoop%E8%BF%9B%E9%98%B6%E4%B9%8B%E8%B7%AF/
 4 EMAIL:y1053419035@qq.com
 5 */
 6 package cn.org.yinzhengjie.hdfs;
 7
 8 import org.apache.hadoop.net.DNSToSwitchMapping;
 9 import java.util.ArrayList;
10 import java.util.List;
11 /**
12  *hadoop副本放置策略：(3副本情况)
13  *      1、在本地机架的一个节点放置一个副本    s101-s103    rack1
14  *      2、在其他机架的两个结点放置两个副本    s104-s105    rack2
15  */
16 public class RackAware implements DNSToSwitchMapping {
17     public List<String> resolve(List<String> names) {
18         List<String> list = new ArrayList<String>();
19         for(String name : names){
20             Integer suffix = 0;
21             /**
22              * 第一种情况: names是主机名
23              */
24             if(name.startsWith("s")){
25                 //将s101变为101
26                 suffix = Integer.parseInt(name.substring(1));
27             }
28             /**
29              * 第二种情况：names是ip
30              */
31             else {
32                 suffix = Integer.parseInt(name.substring(name.lastIndexOf(".") + 1));
33             }
34             /**
35              *  我们的策略是主机位大于103的就放在第一个机会上，即"/rack1",否则就放在第二个机柜上上，即"/rack2"
36              */
37             if(suffix <= 103){
38                 // /rack1/s102
39                 list.add("/rack1");
40             }
41             else {
42                 // /rack2/s105
43                 list.add("/rack2");
44             }
45         }
46         return list;
47     }
48     /**
49      * 下面的两个方法空实现即可。不用搭理它们，咱们这里用不到他们两个方法
50      */
51     public void reloadCachedMappings() {}
52     public void reloadCachedMappings(List<String> names) {}
53 }

[yinzhengjie@s101 ~]$ more `which xrsync.sh`
#!/bin/bash
#@author :yinzhengjie
#blog:http://www.cnblogs.com/yinzhengjie
#EMAIL:y1053419035@qq.com#判断用户是否传参
if [ $# -lt 1 ];thenecho "请输入参数";exit
fi#获取文件路径
file=$@#获取子路径
filename=`basename $file`#获取父路径
dirpath=`dirname $file`#获取完整路径
cd $dirpath
fullpath=`pwd -P`#同步文件到DataNode
for (( i=102;i<=105;i++ ))
do#使终端变绿色 tput setaf 2echo =========== s$i %file ===========#使终端变回原来的颜色，即白灰色tput setaf 7#远程执行命令rsync -lr $filename `whoami`@s$i:$fullpath#判断命令是否执行成功if [ $? == 0 ];thenecho "命令执行成功"fi
done
[yinzhengjie@s101 ~]$
[yinzhengjie@s101 ~]$ xrsync.sh /soft/hadoop/etc/hadoop/core-site.xml
=========== s102 %file ===========
命令执行成功
=========== s103 %file ===========
命令执行成功
=========== s104 %file ===========
命令执行成功
=========== s105 %file ===========
命令执行成功
[yinzhengjie@s101 ~]$ xrsync.sh /soft/hadoop/etc/hadoop/slaves
=========== s102 %file ===========
命令执行成功
=========== s103 %file ===========
命令执行成功
=========== s104 %file ===========
命令执行成功
=========== s105 %file ===========
命令执行成功
[yinzhengjie@s101 ~]$
[yinzhengjie@s101 ~]$ xrsync.sh /soft/hadoop/share/hadoop/common/lib/MyHbase-1.0-SNAPSHOT.jar
=========== s102 %file ===========
命令执行成功
=========== s103 %file ===========
命令执行成功
=========== s104 %file ===========
命令执行成功
=========== s105 %file ===========
命令执行成功
[yinzhengjie@s101 ~]$