Keepalived介绍
1. Keepalived 介绍
Keepalived 起初是转为 LVS 设计的专门用来监控集群系统中各个服务节点的状态，后来又加入了 VRRP 的功能，VRRP 是 Virtual Router Redundancy Protocol（虚拟路由器冗余协议）的缩写，VRRP 出现的目的是为了解决静态路由出现的单点故障问题，它能保证网络的不间断、稳定的运行，所以 Keepalived 一方面具有 LVS cluster nodes healthchecks 功能，又具有 LVS directors failover 功能
一般安装 Keepalived 是在高可用服务器对之间安装，这个服务器不一定是调度器，也可以是 web 服务器，数据库服务器，存储服务器等。
2. Keepalived 故障切换转移原理
Keepalived Directors 之间的故障切换转移是通过 VRRP 协议来实现的。
在 Keepalived Directors 正常工作时，主 Director 节点会不断的向备节点广播心跳消息，用以告诉节点自己还活着，当主节点发生故障时，备节点就无法继续检测到主节点的心跳，进而调用自身的接管程序，接管主节点的 IP 资源及服务。当主节点恢复故障时，备节点会释放主节点故障时自身接管的 IP 资源及服务，恢复到原来的自身的备用角色。
Keepalived配置
Keepalived 官方站点：，
官方文档是：
1. 安装 Keepalived
# 下载软件并安装
wget http://www.keepalived.org/software/keepalived-1.1.17.tar.gz
ll /usr/usr/linux # 检查 link，如果没有可能 kernel-devel 包没装
tar zxf keepalived-1.1.17.tar.gz
cd keepalived-1.1.17 && ./configure
make && make install
# 配置规范启动
cp /usr/local/etc/rc.d/init.d/keepalived /etc/init.d/ # 启动脚本命令
cp /usr/local/etc/sysconfig/keepalived /etc/sysconfig/ # 配置启动脚本的参数
mkdir /etc/keepalived # 创建默认的 keepalived 配置文件路径
cp /usr/local/etc/keepalived/keepalived.conf /etc/keepalived # 拷贝配置模板
cp /usr/local/sbin/keepalived /usr/sbin
/etc/init.d/keepalived start
ps -ef | grep keepalived
/etc/init.d/keepalived stop # 成功后，停止服务，因为是根据默认配置文件启动
2. Keepalived 配置文件
文章：
! Configuration File for keepalived global_defs { notification_email { 1160636144@qq.com } notification_email_from aa@qq smtp_server 192.168.100.100 smtp_connect_timeout 30 router_id LVS_181 } vrrp_instance VI_1 { state MASTER interface eth1 virtual_router_id 100 priority 150 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.100.100 } } vrrp_instance VI_2 { state BACKUP interface eth1 virtual_router_id 200 priority 100 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.100.200 } } | ! Configuration File for keepalived global_defs { notification_email { 1160636144@qq.com } notification_email_from aa@qq smtp_server 192.168.100.100 smtp_connect_timeout 30 router_id LVS_182 } vrrp_instance VI_1 { state BACKUP interface eth1 virtual_router_id 100 priority 100 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.100.100 } } vrrp_instance VI_2 { state MASTER interface eth1 virtual_router_id 200 priority 150 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.100.200 } } |
2. LVS DR + Keepalived
! Configuration File for keepalived global_defs { notification_email { 1160636144@qq.com } notification_email_from aa@qq smtp_server 192.168.100.100 smtp_connect_timeout 30 router_id LVS_181 } vrrp_instance VI_1 { state MASTER interface eth1 virtual_router_id 100 priority 150 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.100.100/24 } } virtual_server 192.168.100.100 80 { delay_loop 6 lb_algo wrr lb_kind DR nat_mask 255.255.255.0 persistence_timeout 50 protocol TCP real_server 192.168.100.183 80{ weight 1 TCP_CHECK { connect_timeout 8 nb_get_retry 3 delay_before_retry 3 connect_port 80 } } real_server 192.168.100.184 80{ weight 1 TCP_CHECK { connect_timeout 8 nb_get_retry 3 delay_before_retry 3 connect_port 80 } } } | ! Configuration File for keepalived global_defs { notification_email { 1160636144@qq.com } notification_email_from aa@qq smtp_server 192.168.100.100 smtp_connect_timeout 30 router_id LVS_182 } vrrp_instance VI_1 { state BACKUP interface eth1 virtual_router_id 100 priority 100 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.100.100/24 } } virtual_server 192.168.100.100 80 { delay_loop 6 lb_algo wrr lb_kind DR nat_mask 255.255.255.0 persistence_timeout 50 protocol TCP real_server 192.168.100.183 80 { weight 1 TCP_CHECK { connect_timeout 8 nb_get_retry 3 delay_before_retry 3 connect_port 80 } } real_server 192.168.100.184 80 { weight 1 TCP_CHECK { connect_timeout 8 nb_get_retry 3 delay_before_retry 3 connect_port 80 } } } |
| 名称 | 接口 | IP | 用途 |
MASTER | eth0 | 10.0.0.19 | 用于 WLAN 数据转发 |
eth1 | 192.168.1.19 | 用于 LAN 数据转发 | |
eth2 | 192.168.2.19 | 用于 LB 间心跳连接 | |
vip | 10.0.0.29 | 提供服务 | |
BACKUP | eth0 | 10.0.0.16 | 用于 WLAN 数据转发 |
eth1 | 192.168.1.16 | 用于 LAN 数据转发 | |
eth2 | 192.168.2.16 | 用于 LB 间心跳连接 | |
vip | 10.0.0.29 | ||
RealServer01 | eth0 | 10.0.0.17 | 用于 WLAN 数据转发 |
eth1 | 192.168.1.17 | 用于 LAN 数据转发 | |
BACKUP | eth0 | 10.0.0.18 | 用于 WLAN 数据转发 |
eth1 | 192.168.1.18 | 用于 LAN 数据转发 |