Keepalived + LVS/DR
说明
- Keepalived：可以踢出掉故障服务
- Keepalived：可以实现主从切换，解决单点故障
实验环境
- 四台主机：Linux Centos 6.4 32位
- 两台Director：LVS+Keepalived
- 两台Web：Apache
环境搭建操作
web server 端
1、添加虚拟IP脚本
vim /usr/local/sbin/lvs_dr.sh
#/bin/bash vip=192.168.1.100 # 把vip绑定在lo上，是为了实现rs直接把结果返回给客户端 ifconfig lo:0 $vip broadcast $vip netmask 255.255.255.255 up route add -host $vip lo:0 # 以下操作为更改arp内核参数，目的是为了让rs顺利发送mac地址给客户端 echo "1">/proc/sys/net/ipv4/conf/lo/arp_ignore echo "2">/proc/sys/net/ipv4/conf/lo/arp_announce echo "1">/proc/sys/net/ipv4/conf/all/arp_ignore echo "2">/proc/sys/net/ipv4/conf/all/arp_announce # 更改内核配置文件之后生效命令，可以不加 sysctl -a 查看所有内核参数 # sysctl -p
2、执行脚本
sh /usr/local/sbin/lvs_dr.sh
主 Director
1、安装服务
yum -y install keepalived.i686 0:1.2.7-3.el6
yum -y install ipvsadm.i686
2、开启路由转发功能
echo 1 > /proc/sys/net/ipv4/ip_forward
3、配置Keepalived配置文件
vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived vrrp_instance VI_1 { # 备用服务器上为 BACKUP state MASTER # 公网的网卡 interface eth0 # 自定义id数值 virtual_router_id 51 # 权重值、主要高于slave priority 100 # 检测服务器状态间隔时间 advert_int 1 authentication { # 密码类型 auth_type PASS # 密码 auth_pass 1111 } virtual_ipaddress { # 虚拟IP地址，可以为多个 192.168.1.100 } } # 配置VIP virtual_server 192.168.1.100 80 { # 每隔6秒查询realserver状态 delay_loop 6 # LVS算法 lb_algo wlc # Direct Route lb_kind DR # 同一个IP的链接0秒内被分配到同一台realserver persistence_timeout 0 # 用TCP协议检查realserver状态 protocol TCP # 配置realserver real_server 192.168.1.111 80 { # 权重 weight 100 TCP_CHECK { # 10秒无响应超时 connect_timeout 10 nb_get_retry 3 delay_before_retry 3 connect_port 80 } } # 配置realserver real_server 192.168.1.115 80 { # 权重 weight 100 # 检测 TCP_CHECK { # 10秒无响应超时 connect_timeout 10 nb_get_retry 3 delay_before_retry 3 connect_port 80 } } }
4、启动服务：先启动主后启动从
/etc/init.d/keepalived start
从 Director
1、安装服务
yum -y install keepalived.i686 0:1.2.7-3.el6
yum -y install ipvsadm.i686
2、开启路由转发功能
echo 1 > /proc/sys/net/ipv4/ip_forward
3、配置Keepalived配置文件
vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived vrrp_instance VI_1 { # 主用服务器上为 MASTER state BACKUP # 公网的网卡 interface eth0 # 自定义id数值 virtual_router_id 51 # 权重值、主要高于slave priority 90 # 检测服务器状态间隔时间 advert_int 1 authentication { # 密码类型 auth_type PASS # 密码 auth_pass 1111 } virtual_ipaddress { # 虚拟IP地址，可以为多个 192.168.1.100 } } # 配置VIP virtual_server 192.168.1.100 80 { # 每隔6秒查询realserver状态 delay_loop 6 # LVS算法 lb_algo wlc # Direct Route lb_kind DR # 同一个IP的链接0秒内被分配到同一台realserver persistence_timeout 0 # 用TCP协议检查realserver状态 protocol TCP # 配置realserver real_server 192.168.1.111 80 { # 权重 weight 100 TCP_CHECK { # 10秒无响应超时 connect_timeout 10 nb_get_retry 3 delay_before_retry 3 connect_port 80 } } # 配置realserver real_server 192.168.1.115 80 { # 权重 weight 100 # 检测 TCP_CHECK { # 10秒无响应超时 connect_timeout 10 nb_get_retry 3 delay_before_retry 3 connect_port 80 } } }
4、启动服务：先启动主后启动从
/etc/init.d/keepalived start
查询状态
命令：ipvsadm -l IP Virtual Server version 1.2.1 (size=4096) Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:Port Forward Weight ActiveConn InActConn TCP 192.168.1.100:http wlc -> 192.168.1.111:http Route 100 0 0 -> 192.168.1.115:http Route 100 0 0
命令：ip addr 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 00:0c:29:67:0e:20 brd ff:ff:ff:ff:ff:ff inet 192.168.1.160/24 brd 192.168.1.255 scope global eth0 inet 192.168.1.100/32 scope global eth0 inet6 fe80::20c:29ff:fe67:e20/64 scope link valid_lft forever preferred_lft forever
命令：ipvsadm -l IP Virtual Server version 1.2.1 (size=4096) Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:Port Forward Weight ActiveConn InActConn TCP 192.168.1.100:http wlc -> 192.168.1.111:http Route 100 0 0 -> 192.168.1.115:http Route 100 0 0
命令：ip addr 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 00:0c:29:9e:70:1e brd ff:ff:ff:ff:ff:ff inet 192.168.1.161/24 brd 192.168.1.255 scope global eth0 inet6 fe80::20c:29ff:fe9e:701e/64 scope link valid_lft forever preferred_lft forever
命令：ifconfig lo:0 Link encap:Local Loopback inet addr:192.168.1.100 Mask:255.255.255.255 UP LOOPBACK RUNNING MTU:16436 Metric:1
测试
http://192.168.1.100/ LVS 1 http://192.168.1.100/ LVS 2 http://192.168.1.100/ LVS 1 http://192.168.1.100/ LVS 2
#---------------------------单点故障-------------------------------# Dir 主 端：ifdown eth0 关闭网卡 # 查看IP飘逸192.168.1.100 Dir 从端：ip addr 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 00:0c:29:9e:70:1e brd ff:ff:ff:ff:ff:ff inet 192.168.1.161/24 brd 192.168.1.255 scope global eth0 inet 192.168.1.100/32 scope global eth0 inet6 fe80::20c:29ff:fe9e:701e/64 scope link valid_lft forever preferred_lft forever # 查看日志 主端：tail -f /var/log/messages Dec 24 02:36:18 localhost Keepalived_healthcheckers[1916]: Netlink reflector reports IP 192.168.1.100 added #------------------------------------------------------------------# #---------------------------恢复单点故障-----------------------------# Dir 主 端：ifup eth0 启动网卡 # 查看IP飘逸192.168.1.100 Dir 主 端： ip addr 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 00:0c:29:67:0e:20 brd ff:ff:ff:ff:ff:ff inet 192.168.1.160/24 brd 192.168.1.255 scope global eth0 inet 192.168.1.100/32 scope global eth0 inet6 fe80::20c:29ff:fe67:e20/64 scope link valid_lft forever preferred_lft forever # 查看日志 Dir 从 端： tail -f /var/log/messages Dec 24 02:36:23 localhost Keepalived_vrrp[1917]: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth0 for 192.168.1.100 Dec 24 02:48:02 localhost Keepalived_vrrp[1917]: VRRP_Instance(VI_1) Received higher prio advert Dec 24 02:48:02 localhost Keepalived_vrrp[1917]: VRRP_Instance(VI_1) Entering BACKUP STATE Dec 24 02:48:02 localhost Keepalived_vrrp[1917]: VRRP_Instance(VI_1) removing protocol VIPs. Dec 24 02:48:02 localhost Keepalived_healthcheckers[1916]: Netlink reflector reports IP 192.168.1.100 removed #------------------------------------------------------------------#