通过rsycn实现数据同步

一、实验要求

1. 备份机器需要每天凌晨1:03分定时同步MIS服务器的/app/java_project目录下的所有文件。
2. 要求记录同步日志，方便同步失败分析原因。

二、任务分析

1.使用crontab来编写计划任务

2.使用rsync来进行远程同步

3.因为是定时任务，rsync基于ssh服务，所以需要两台服务器设置ssh免密登录

三、实验拓扑图

四、实验环境介绍

IP为128的服务器为MIS服务器，存放代码的目录为/app/java_project,此目录需要去备份

IP为129的服务器为代码备份服务器，需要把128服务器上的代码备份到/backup/app/java_project

五、实验具体步骤

1.两台服务器配置ssh免密登录

     需要129服务器能够免密登录到128上

[root@back ~]# ssh-keygen         //生成密钥对
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa): 
Created directory '/root/.ssh'.
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in /root/.ssh/id_rsa.
Your public key has been saved in /root/.ssh/id_rsa.pub.
The key fingerprint is:
0d:8c:ee:fe:38:88:44:f9:1c:a3:8f:18:23:01:06:83 root@back
The key's randomart image is:
+--[ RSA 2048]----+
|=                |
|Eo     o         |
|o  .  . o        |
|. o o.   o       |
| o + o. S .      |
|+ o o.           |
|.= + ..          |
|. o o...         |
|      oo.        |
+-----------------+
 
[root@back .ssh]# ssh-copy-id -i /root/.ssh/id_rsa.pub root@192.168.189.128        //把公钥远程拷贝到128主机上
The authenticity of host '192.168.189.128 (192.168.189.128)' can't be established.
RSA key fingerprint is df:28:9d:09:a3:bf:52:a6:e5:ce:f2:a4:04:0d:b8:cc.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.189.128' (RSA) to the list of known hosts.
root@192.168.189.128's password: 
Now try logging into the machine, with "ssh 'root@192.168.189.128'", and check in:

  .ssh/authorized_keys

to make sure we haven't added extra keys that you weren't expecting.

[root@back .ssh]# ssh root@192.168.189.128
Last login: Sun Jul 21 22:45:44 2019 from 192.168.189.1
//测试ssh免密登录完成

2.开启rsync服务(MIS服务器上)

相关的文档可看https://www.cnblogs.com/feng0919/p/11223473.html

[root@MIS .ssh]# yum install rsync
已安装:
  rsync.x86_64 0:3.0.6-12.el6                                                                                                                                                         
完毕！

[root@MIS .ssh]# vim /etc/rsyncd.conf

[java]
path = /app/java_project/
log file = /tmp/rsync.log

[root@MIS .ssh]# rsync --daemon

3.通过脚本编写计划任务

[root@back ~]# vim rstnc.sh

#!/bin/bash
rsync -a 192.168.189.128::java /backup/app/java_project/

[root@back ~]# chmod +x rstnc.sh 
[root@back ~]# crontab -e
no crontab for root - using an empty one

03 01 * * * /root/rsync.sh &>/dev/null