###
1、keepalived软件能干什么
Keepalived软件起初是专为LVS负载均衡软件设计的，
用来管理并监控LVS集群系统中各个服务节点的状态，后来又加入了可以实现高可用的VRRP功能
①. 管理LVS负载均衡软件
②. 实现对LVS集群节点健康检查功能
③. 作为系统网络服务的高可用功能
2、keepalived软件工作原理
1）VRRP协议，全称Virtual Router Redundancy Protocol，中文名为虚拟路由冗余协议，VRRP的出现是为了解决静态路由的单点故障。 2）VRRP是用过IP多播的方式（默认多播地址（224.0.0.18））实现高可用对之间通信的。 3）工作时主节点发包，备节点接包，当备节点接收不到主节点发的数据包的时候，就启动接管程序接管主节点的资源。备节点可以有多个，通过优先级竞选，但一般Keepalived系统运维工作中都是一对。
3、环境配置
web01+lb01 192.168.2.140[root@test01 ~] web02+lb02 192.168.2.141[root@test02 ~]
4、部署keepalived
4.1、查看服务器ip信息
[root@test01 ~]# ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 00:0c:29:c0:74:21 brd ff:ff:ff:ff:ff:ff inet 192.168.2.140/24 brd 192.168.2.255 scope global eth0 valid_lft forever preferred_lft forever inet6 fe80::20c:29ff:fec0:7421/64 scope link valid_lft forever preferred_lft forever
[root@test02 ~]# ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 00:0c:29:c0:74:21 brd ff:ff:ff:ff:ff:ff inet 192.168.2.141/24 brd 192.168.2.255 scope global eth0 valid_lft forever preferred_lft forever inet6 fe80::20c:29ff:fec0:7421/64 scope link valid_lft forever preferred_lft forever
4.2、安装keepalived
#【test01、test02服务器都需要操作】 yum install -y keepalived cd /etc/keepalived/ cp keepalived.conf{,_bak}
4.3、主服务器keepalived配置文件【test01服务器】
[root@test01 ~]# cat > /etc/keepalived/keepalived.conf<<EOF ! Configuration File for keepalived global_defs { router_id LVS_01 } # vrrp_instance，实例名出自实例组group所包含的那些名字。 vrrp_instance VI_1 { # 定义keepalived实例信息，主备节点实例标识相同 state MASTER # 定义实例中主备状态角色（MASTER/BACKUP） interface eth0 # 设置主备服务器IP地址防止网卡位置 virtual_router_id 51 # 虚拟路由ID标识，不同实例不同，主备相同 priority 150 # 优先级，高优先级竞选为master advert_int 1 # 检查间隔，默认1秒 authentication { # 主备之间通过认证建立连接 auth_type PASS auth_pass 1111 } virtual_ipaddress { # 定义主备服务器之间使用的虚拟IP，可多设，每行一个 192.168.2.210/24 } } #虚拟服务器virtual_server定义块 ，虚拟服务器定义是keepalived框架最重要的项目了，是keepalived.conf必不可少的部分。 该部分是用来管理LVS的，是实现keepalive和LVS相结合的模块。
#ipvsadm命令可以实现的管理在这里都可以通过参数配置实现，注意：real_server是被包含在viyual_server模块中的，是子模块。
virtual_server 192.168.2.210 80 { # 定义对外提供服务的LVS的VIP以及port delay_loop 6 # 设置健康检查时间，单位是秒 lb_algo wrr # lvs调度算法rr|wrr|lc|wlc|lblc|sh|dh lb_kind DR # 负载均衡转发规则NAT|DR|RUN nat_mask 255.255.255.0 persistence_timeout 50 # 会话保持时间 protocol TCP # 指定转发协议类型，有TCP和UDP两种 real_server 192.168.2.140 80 { # 指定real server1的IP地址【监控192.168.2.140服务器80端口】 weight 1 TCP_CHECK { connect_timeout 8 # 连接超时时间 nb_get_retry 3 # 重连次数 delay_before_retry 3 # 重连间隔时间 connect_port 80 #健康检查的端口 } } real_server 192.168.2.141 80 { weight 1 TCP_CHECK { connect_timeout 8 nb_get_retry 3 delay_before_retry 3 connect_port 80 } } } EOF
4.4、从服务器keeplived配置文件【test02】
[root@test02 ~]# cat > /etc/keepalived/keepalived.conf<<EOF ! Configuration File for keepalived global_defs { router_id LVS_02 } vrrp_instance VI_1 { state BACKUP interface eth0 virtual_router_id 51 priority 100 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.2.210/24 } } virtual_server 192.168.2.210 80 { delay_loop 6 lb_algo wrr lb_kind DR nat_mask 255.255.255.0 persistence_timeout 50 protocol TCP real_server 192.168.2.140 80 { weight 1 TCP_CHECK { connect_timeout 8 nb_get_retry 3 delay_before_retry 3 connect_port 80 } } real_server 192.168.2.141 80 { weight 1 TCP_CHECK { connect_timeout 8 nb_get_retry 3 delay_before_retry 3 connect_port 80 } } } EOF
4.5、启动keepalived
systemctl start keepalived.service
4.6、查看服务器虚拟ip
[root@test01 ~]# ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 00:0c:29:d6:8f:8e brd ff:ff:ff:ff:ff:ff inet 192.168.2.140/24 brd 192.168.2.255 scope global eth0 valid_lft forever preferred_lft forever inet 192.168.2.210/24 scope global secondary eth0 valid_lft forever preferred_lft forever inet6 fe80::20c:29ff:fed6:8f8e/64 scope link valid_lft forever preferred_lft forever [root@test02 ~]# ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 00:0c:29:c0:74:21 brd ff:ff:ff:ff:ff:ff inet 192.168.2.141/24 brd 192.168.2.255 scope global eth0 valid_lft forever preferred_lft forever inet6 fe80::20c:29ff:fec0:7421/64 scope link valid_lft forever preferred_lft forever
5、测试keepalived
5.1、停止主服务器keepalived
[root@test01 ~]# systemctl stop keepalived
5.2、查看虚拟ip情况
[root@test01 ~]# ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 00:0c:29:d6:8f:8e brd ff:ff:ff:ff:ff:ff inet 192.168.2.140/24 brd 192.168.2.255 scope global eth0 valid_lft forever preferred_lft forever inet6 fe80::20c:29ff:fed6:8f8e/64 scope link valid_lft forever preferred_lft forever [root@test02 ~]# ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 00:0c:29:c0:74:21 brd ff:ff:ff:ff:ff:ff inet 192.168.2.141/24 brd 192.168.2.255 scope global eth0 valid_lft forever preferred_lft forever inet 192.168.2.210/24 scope global secondary eth0 valid_lft forever preferred_lft forever inet6 fe80::20c:29ff:fec0:7421/64 scope link valid_lft forever preferred_lft forever
###