文章目录
一、keepalive概述
1.1 keepalive案例
- 企业应用中,单台服务器承担应用存在
- 单点故障的危险单点故障一旦发生,企业服务将发生中断,造成极大的危害
1.2 keepalive工具介绍
专为LVS和HA设计的一款健康检查工具
- 支持故障自动切换(Failover)
- 支持节点健康状态检查(Health Checking)
- 官方网站: http://www.keepalived.org/
1.3 keepalive原理
Keepalived采用VRRP热备份协议,实现Linux服务器的多机热备功能
VRRP(虚拟路由冗余协议)是针对路由器的一种备份解决方案
- 由多台路由器组成一个热备组,通过共用的虚拟IP地址对外提供服务
- 每个热备组内同时只有一台主路由器提供服务,其他路由器处于冗余状态
- 若当前在线的路由器失效,则其他路由器会根据设置的优先级自动接替虚拟IP地址,继续提供服务
1.4 keepalive案例
Keepalived可实现多机热备,每个热备组可有多台服务器
双机热备的故障切换是由虚拟IP地址的漂移来实现,适用于各种应用服务器
实现基于Web服务的双机热备
- 漂移地址:192.168.10.100
- 主、备服务器:192.168.10.11、192.168.10.12
- 提供的应用服务:Web
1.5 keepalive安装与启动
-
首先在LVS群集环境中应用是,需要用到ipvsadm管理工具
modprobe ip_vs cat /proc/net/ip_vs yum -y install ipvsadm
-
keepalive的安装
tar zxvf keepalived-2.0.13.tar.gz cd keepalived-2.0.13/ ./configure --prefix=/ make && make install cd /keepalived/etc/init.d/keepalived /etc/init.d/ systemctl enable keepalived.service
-
keepalive配置文件
扫描二维码关注公众号,回复: 12651281 查看本文章vi /etc/keepalived/keepalived.conf ! Configuration File for keepalived global_defs { router_id lvs_01 } vrrp_instance vi_1 { state MASTER interface ens33 virtual_router_id 51 priority 110 advert_int 1 authentication { auth_type PASS auth_pass 6666 } virtual_ipaddress { 192.168.10.100 } } virtual_server 192.168.10.100 80 { delay_loop 6 lb_algo rr lb_kind DR persistence_timeout 6 protocol TCP real_server 192.168.10.13 80 { weight 1 TCP_CHECK { connect_port 80 connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } } real_server 192.168.10.14 80 { weight 1 TCP_CHECK { connect_port 80 connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } } }
二、部署LVS和keepalive群集
2.1 共享服务器的配置
yum -y install nfs-utils rpcbind
mkdir /opt/web1
mkdir /opt/web2
echo "<h1>this is web1</h1>" >> /opt/web1/index.html
echo "<h1>this is web2</h1>" >> /opt/web2 /index.html
vi /etc/exports
/opt/web1 192.168.10.13(ro)
/opt/web2 192.168.10.14(ro)
systemctl start nfs
systemctl restart rpcbind
showmount -e
2.2 web节点上面的配置
-
挂载内容,开启httpd服务
yum -y install httpd mount 192.168.10.19:/opt/web1 /var/www/html df -Th curl http://localhost
-
配置节点
vi web1.sh #!/bin/bash # lvs web1 ifconfig lo:0 192.168.10.100 broadcast 192.168.10.100 netmask 255.255.255.255 up route add -host 192.168.10.100 dev lo:0 echo "1" > /proc/sys/net/ipv4/conf/lo/arp_ignore echo "1" > /proc/sys/net/ipv4/conf/all/arp_ignore echo "2" > /proc/sys/net/ipv4/conf/lo/arp_announce echo "2" > /proc/sys/net/ipv4/conf/all/arp_announce sysctl -p &> /dev/null
2.3 调度器上的配置
modprobe ip_vs
cat /proc/net/ip_vs
yum -y install ipvsadm
tar zxvf keepalived-2.0.13.tar.gz
cd keepalived-2.0.13/
./configure --prefix=/
make && make install
cd /keepalived/etc/init.d/keepalived /etc/init.d/
systemctl enable keepalived.service
vi /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
router_id lvs_01
}
vrrp_instance vi_1 {
state MASTER
interface ens33
virtual_router_id 51
priority 110
advert_int 1
authentication {
auth_type PASS
auth_pass 6666
}
virtual_ipaddress {
192.168.10.100
}
}
virtual_server 192.168.10.100 80 {
delay_loop 6
lb_algo rr
lb_kind DR
persistence_timeout 6
protocol TCP
real_server 192.168.10.13 80 {
weight 1
TCP_CHECK {
connect_port 80
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
real_server 192.168.10.14 80 {
weight 1
TCP_CHECK {
connect_port 80
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
}
systemctl start keepalived
备用调度器上面的配置与主配置相似,但是保证服务能够正常的运行,需要保证router_id的唯一性,以及优先级的不同。需要修改如下的配置:
vi /etc/keepalived/keepalive.conf
router_id lvs_02
state BACKUP
priority 105
2.4 群集功能的验证
在浏览器上面访问虚拟地址:
在主备调度器上面可以查询到网页访问情况:
为了验证备份调度器的功能,我们可以手动关闭主动调度器的keepalive功能
systemctl stop keepalive
可以发现虚拟地址漂移到了备份的调度器上面。
再重新启动原主备调度器的keepalive功能,又可以发现地址重新回到了原主备调度器上面。