lvs keepalived apache
LVS(DR) + Keepalived 实现负载均衡高可用
一、为什么要使 用负载均衡技术?
1、 系统高可用性
2、 系统可扩展性
3、 负载均衡能力
LVS+keepalived能很好的实现以上的要求,LVS提 供负载均衡,keepalived提供健康检查,故障转移,提高系统的可用性!采用这样的架构以后 很容易对现有系统进行扩展,只要在后端添加或者减少realserver,只要更改lvs的 配置文件,并能实现无缝配置变更!
二、LVS+Keepalived介绍
1、 LVS
LVS是一个开源的软件,可以实现LINUX平台下的简单负载均衡。LVS是Linux Virtual Server的缩写,意思是Linux虚拟服务器。目前有三种IP负 载均衡技术(VS/NAT、VS/TUN和VS/DR);八种调度算法(rr,wrr,lc,wlc,lblc,lblcr,dh,sh)。
2、 keepalived
Keepalived 是运行在lvs 之上,它的主要功能是实现真实机的故障隔离及负载均衡器间的失败 切换,提高系统的可用性。
一、环境说明
本次试验使用的是2台前端代理服务器(LVS) 加上 keepalived,后端为了方便,使用apache来发布网页,达到测试的目的。
操作系统:centos7 64位
软件源:阿里云
2台服务器(LVS1、LVS2)安装 keepalived 和安装LVS 来反向代理
2台服务器(web1、web2)安装 apache 来提供服务
服务器的防火墙和selinux全部关闭
LVS1 IP:192.168.163.158
LVS2 IP:192.168.163.161
web1 IP:192.168.163.159
web2 IP:192.168.163.160
虚拟IP: 192.168.163.200
拓扑图如下:
二、环境安装
首先配置web服务器
1、首先为后端的2台web服务器安装apache
[root@web1 ~]# yum install -y httpd
[root@web2 ~]# yum install -y httpd
2、创建各自的网页
[root@web1 ~]# echo "web1:192.168.163.159" > /var/www/html/index.html
[root@web2 ~]# echo "web2:192.168.163.160" > /var/www/html/index.html
3、启动服务
[root@web1 ~]# systemctl start httpd
[root@web2 ~]# systemctl start httpd
4、编写脚本,为web服务器设置虚拟IP以及设置抑制ARP包
[root@web1 ~]# vim /root/VIP.sh
- #!/bin/bash
- VIP=192.168.163.200 #这个为你要设置的VIP
- case $1 in
- start)
- ifconfig lo:0 $VIP netmask 255.255.255.255 broadcast $VIP
- /sbin/route add -host $VIP dev lo:0
- 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
- sysctl -p >/dev/null 2>&1
- echo "RealServer Start OK"
- ;;
- stop)
- ifconfig lo:0 down
- route del $IP >/dev/null 2>&1
- echo "0" >/proc/sys/net/ipv4/conf/lo/arp_ignore
- echo "0" >/proc/sys/net/ipv4/conf/lo/arp_announce
- echo "0" >/proc/sys/net/ipv4/conf/all/arp_ignore
- echo "0" >/proc/sys/net/ipv4/conf/all/arp_announce
- echo "RealServer Stoped"
- ;;
- *)
- echo "Usage: $0 {start|stop}"
- exit 1
- esac
添加执行权限并执行该脚本
[root@web1 ~]# chmod a+x VIP.sh
[root@web1 ~]# bash /root/VIP.sh start
在web2上也执行该操作
在LVS服务器安装 LVS 和 Keepalived
1、安装软件包
[root@LVS1 ~]# yum install -y ipvsadm keepalived
[root@LVS2 ~]# yum install -y ipvsadm keepalived
2、编辑 LVS1的 keepalived 配置文件
[root@LVS1 ~]# vim /etc/keepalived/keepalived.conf
- ! Configuration File for keepalived
- global_defs {
- notification_email {
- root@localhost
- }
- notification_email_from keepalived@localhost
- smtp_server 127.0.0.1
- smtp_connect_timeout 30
- router_id LVS
- vrrp_mcast_group4 224.0.100.19
- }
- vrrp_instance VI_1 {
- state BACKUP
- interface ens32
- virtual_router_id 51
- priority 100
- nopreempt
- advert_int 1
- authentication {
- auth_type PASS
- auth_pass xhk
- }
- virtual_ipaddress {
- 192.168.163.200 dev ens32
- }
- }
- virtual_server 192.168.163.200 80 { # 定义转移ip端口80的集群服务
- delay_loop 3
- lb_algo rr
- lb_kind DR
- protocol TCP
- sorry_server 127.0.0.1 80
- real_server 192.168.163.159 80 { # 定义集群服务包含的RS 1
- weight 1 # 权重为1
- HTTP_GET { # 定义RS1的健康状态检测
- url {
- path /
- status_code 200
- }
- connect_timeout 1
- nb_get_retry 3
- delay_before_retry 1
- }
- }
- real_server 192.168.163.160 80 { # 定义集群服务包含的RS 2
- weight 1 # 权重为1
- HTTP_GET { # 定义RS2的健康状态检测
- url {
- path /
- status_code 200
- }
- connect_timeout 1
- nb_get_retry 3
- delay_before_retry 1
- }
- }
- }
3、编辑 LVS2的 keepalived 配置文件
[root@LVS2 ~]# vim /etc/keepalived/keepalived.conf
- ! Configuration File for keepalived
- global_defs {
- notification_email {
- root@localhost
- }
- notification_email_from keepalived@localhost
- smtp_server 127.0.0.1
- smtp_connect_timeout 30
- router_id LVS
- vrrp_mcast_group4 224.0.100.19
- }
- vrrp_instance VI_1 {
- state BACKUP
- interface ens32
- virtual_router_id 51
- priority 99
- nopreempt
- advert_int 1
- authentication {
- auth_type PASS
- auth_pass xhk
- }
- virtual_ipaddress {
- 192.168.163.200 dev ens32
- }
- }
- virtual_server 192.168.163.200 80 { # 定义转移ip端口80的集群服务
- delay_loop 3
- lb_algo rr
- lb_kind DR
- protocol TCP
- sorry_server 127.0.0.1 80
- real_server 192.168.163.159 80 { # 定义集群服务包含的RS 1
- weight 1 # 权重为1
- HTTP_GET { # 定义RS1的健康状态检测
- url {
- path /
- status_code 200
- }
- connect_timeout 1
- nb_get_retry 3
- delay_before_retry 1
- }
- }
- real_server 192.168.163.160 80 { # 定义集群服务包含的RS 2
- weight 1 # 权重为1
- HTTP_GET { # 定义RS2的健康状态检测
- url {
- path /
- status_code 200
- }
- connect_timeout 1
- nb_get_retry 3
- delay_before_retry 1
- }
- }
- }
2个配置文件不同的只是优先级的不同,分出MASTER,并且设置了不抢占模式,为的是防止业务切换国语频繁!
4、开启路由转发
[root@LVS1 ~]# echo "1" /proc/sys/net/ipv4/ip_forward
[root@LVS2 ~]# echo "1" /proc/sys/net/ipv4/ip_forward
5、设置虚拟IP
[root@LVS1 ~]# ifconfig lo:0 192.168.113.200 broadcast 192.168.113.200 netmask 255.255.255.255 up
[root@LVS2 ~]# ifconfig lo:0 192.168.113.200 broadcast 192.168.113.200 netmask 255.255.255.255 up
6、启动keepalived服务
[root@LVS1 ~]# systemctl restart keepalived
[root@LVS2 ~]# systemctl restart keepalived
三、测试环节
1、查看keepalived状态
[root@LVS1 ~]# systemctl status keepalived
● keepalived.service - LVS and VRRP High Availability Monitor
Loaded: loaded (/usr/lib/systemd/system/keepalived.service; disabled; vendor preset: disabled)
Active: active (running) since Sun 2017-10-22 01:26:32 EDT; 3min 48s ago
Process: 2656 ExecStart=/usr/sbin/keepalived $KEEPALIVED_OPTIONS (code=exited, status=0/SUCCESS)
Main PID: 2657 (keepalived)
CGroup: /system.slice/keepalived.service
├─2657 /usr/sbin/keepalived -D
├─2658 /usr/sbin/keepalived -D
└─2659 /usr/sbin/keepalived -D
Oct 22 01:26:37 LVS1 Keepalived_vrrp[2659]: Sending gratuitous ARP on ens32 for 192.168.163.200
查看虚拟IP
[root@LVS1 ~]# ip addr sh
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
inet 192.168.113.200/32 brd 192.168.113.200 scope global lo:0
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: ens32: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:5f:46:a6 brd ff:ff:ff:ff:ff:ff
inet 192.168.163.158/24 brd 192.168.163.255 scope global dynamic ens32
valid_lft 1654sec preferred_lft 1654sec
inet 192.168.163.200/32 scope global ens32
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:fe5f:46a6/64 scope link
valid_lft forever preferred_lft forever
访问网页
[root@client ~]# curl 192.168.163.200
web1:192.168.163.159
[root@client ~]# curl 192.168.163.200
web2:192.168.163.160
将LVS1的Keepalived停掉
[root@LVS1 ~]# systemctl stop keepalived
可以看到LVS拿到了VIP
[root@LVS2 ~]# systemctl status keepalived
● keepalived.service - LVS and VRRP High Availability Monitor
Loaded: loaded (/usr/lib/systemd/system/keepalived.service; disabled; vendor preset: disabled)
Active: active (running) since Sun 2017-10-22 01:26:38 EDT; 6min ago
Process: 2553 ExecStart=/usr/sbin/keepalived $KEEPALIVED_OPTIONS (code=exited, status=0/SUCCESS)
Main PID: 2555 (keepalived)
CGroup: /system.slice/keepalived.service
├─2555 /usr/sbin/keepalived -D
├─2556 /usr/sbin/keepalived -D
└─2557 /usr/sbin/keepalived -D
Oct 22 01:32:50 LVS2 Keepalived_vrrp[2557]: Sending gratuitous ARP on ens32 for 192.168.163.200
继续访问网页
[root@client ~]# curl 192.168.163.200
web1:192.168.163.159
[root@client ~]# curl 192.168.163.200
web2:192.168.163.160
测试成功!!!!!!!!!!!!!!!!!!!
来源: http://www.bubuko.com/infodetail-2361513.html