使用Keepalived和HAProxy实现MySQL的高可用负载均衡

在构建高可用性MySQL架构时，使用Keepalived和HAProxy的组合是一种常见的解决方案。Keepalived用于实现故障切换和服务监控，而HAProxy则用于实现负载均衡。本文将详细介绍如何配置Keepalived和HAProxy，以实现MySQL的高可用负载均衡。

安装和配置Keepalived
首先，我们需要在每个MySQL节点上安装和配置Keepalived。Keepalived用于监控MySQL服务，并在主节点故障时自动切换到备用节点。

1. 安装Keepalived：

   sudo apt-get install keepalived
   ```
   
   

2. 配置Keepalived：
   在每个MySQL节点上创建Keepalived配置文件/etc/keepalived/keepalived.conf，并按照以下示例进行配置：

   global_defs {
     router_id MySQL_HA
   }
   
   vrrp_instance VI_1 {
     state BACKUP
     interface eth0
     virtual_router_id 51
     priority 100
     advert_int 1
     authentication {
       auth_type PASS
       auth_pass password
     }
     virtual_ipaddress {
       192.168.1.100
     }
   }
   
   virtual_server 192.168.1.100 3306 {
     delay_loop 6
     lb_algo rr