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keepalived + haproxy 实现web的高可用负载均衡
一、Haproxy简介
人们熟知的软件负载均衡如LVS、HAProxy，各方面性能不亚于硬件负载均衡，HAProxy提供高可用性、负载均衡以及基于TCP和HTTP应用的代理，支持虚拟主机，它是免费、快速并且可靠的一种解决方案。HAProxy特别适用于那些负载特大的web站点，这些站点通常又需要会话保持或七层处理。
HAProxy相比LVS的使用要简单很多，功能方面也很丰富。当前，HAProxy支持两种主要的代理模式:"tcp"也即4层（大多用于邮件服务器、内部协议通信服务器等），和7层（HTTP）。在4层模式 下，HAProxy仅在客户端和服务器之间转发双向流量。7层模式下，HAProxy会分析协议，并且能通过允许、拒绝、交换、增加、修改或者***请求 (request)或者回应(response)里指定内容来控制协议，这种操作要基于特定规则。
HAProxy的负载均衡算法现在也越来越多了，具体有如下8种：
①roundrobin，表示简单的轮询，这个不多说，这个是负载均衡基本都具备的；
②static-rr，表示根据权重，建议关注；
③leastconn，表示最少连接者先处理，建议关注；
④source，表示根据请求源IP，这个跟Nginx的IP_hash机制类似，我们用其作为解决session问题的一种方法
⑤ri，表示根据请求的URI；
⑥rl_param，表示根据请求的URl参数‘balance url_param‘ requires an URL parameter name；
⑦hdr(name)，表示根据HTTP请求头来锁定每一次HTTP请求；
⑧rdp-cookie(name)，表示根据据cookie(name)来锁定并哈希每一次TCP请求。
二、拓扑图
三、安装
1、安装配置haproxy A
[root@90sec ~]# yum -y install haproxy
[root@90sec ~]# cd /etc/haproxy/
[root@90sec haproxy]# cp haproxy.cfg haproxy.cfg.bak ##备份
[root@90sec haproxy]# vim haproxy.cfg
global #全局配置
# local2.* /var/log/haproxy.log
#
log 127.0.0.1 local2 #日志功能，要开启日志服务
chroot /var/lib/haproxy
pidfile /var/run/haproxy.pid
maxconn 4000
user haproxy
group haproxy
daemon #让haproxy以守护进程的方式工作于后台
# turn on stats unix socket
stats socket /var/lib/haproxy/stats
#---------------------------------------------------------------------
# common defaults that all the ‘listen‘ and ‘backend‘ sections will
# use if not designated in their block
#---------------------------------------------------------------------
defaults
mode http #指定haproxy的工作模式
option httplog
option dontlognull
option http-server-close
option forwardfor except 127.0.0.0/8
option redispatch
retries 3
timeout http-request 10s
timeout queue 1m
timeout connect 10s
timeout client 1m
timeout server 1m
timeout http-keep-alive 10s
timeout check 10s
maxconn 3000
#---------------------------------------------------------------------
# main frontend which proxys to the backends
#---------------------------------------------------------------------
listen stats
mode http
bind 0.0.0.0:1080 #绑定端口
stats enable #开启stats功能
stats hide-version # 隐藏版本号
stats uri /admin?status #通过什么样的URL访问
stats realm Haproxy\ Statistics #认证注释信息
stats auth 90sec:admin #认证放松（user：passwd）
stats admin if TRUE #如果认证通过，则赋予权限
acl allow src 192.168.0.0/24 #访问控制
tcp-request content accept if allow
tcp-request content reject
frontend proxy #前端代理
bind *:80 #监听端口
mode http
log global
option httpclose
option logasap
option dontlognull
capture request header Host len 20
capture request header Referer len 60
acl url_static path_beg -i /static/images/javascript/stylesheets
acl url_static path_end -i .jpg .gif .png .css .js .html
use_backend static_servers if url_static
default_backend dynamic_servers
backend static_servers #后端静态web
balance source #算法调度
server web1 172.16.36.130:80 check maxconn 6000
backend dynamic_servers #后端动态调度
balance source
server web2 172.16.36.131:80 check maxconn 6000
配置日志
[root@90sec ~]# vim /etc/rsyslog.conf
$ModLoad imtcp #取消注释
$InputTCPServerRun 514 #取消注释
添加一下行
local2.* /var/log/haproxy.log
[root@90sec ~]# service rsyslog restart
Shutting down system logger: [ OK ]
Starting system logger: [ OK ]
2、安装keepalived
[root@90sec src]# tar xf keepalived-1.2.12.tar.gz
[root@90sec src]# cd keepalived-1.2.12
[root@90sec keepalived-1.2.12]# ./configure --prefix=/usr/local/keepalived --with-dir=/usr/src/kernels/*/
[root@90sec keepalived-1.2.12]# make && make install
[root@90sec keepalived-1.2.12]# mkdir /etc/keepalived
[root@90sec keepalived-1.2.12]# cp -f keepalived/etc/keepalived/keepalived.conf /etc/keepalived/
[root@90sec keepalived-1.2.12]# cp -f keepalived/etc/init.d/keepalived.init /etc/init.d/keepalived
[root@90sec keepalived-1.2.12]# cp -f keepalived/etc/init.d/keepalived.sysconfig /etc/sysconfig/keepalived
[root@90sec keepalived-1.2.12]# cp -f /usr/local/keepalived/sbin/keepalived /sbin/
[root@90sec keepalived-1.2.12]# vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
notification_email {
8888@126.com ##邮件通知
}
notification_email_from root@localhost
smtp_server 127.0.0.1 ##使用本机邮件服务
smtp_connect_timeout 30
router_id LVS_DEVEL
}
vrrp_scrip chk_haproxy { ##判断haproxy服务状态
script "killall -0 haproxy"
interval 1
weight 2
}
vrrp_instance VI_1 {
state MASTER #在A 上是主 ，在B 上是备
interface eth0
virtual_router_id 200 # 路由ID
priority 100 #优先级
advert_int 1
authentication { #路由之间认证方式
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.83.100/24 dev eth0 label eth0:0 #VIP
}
track_scripts { #追踪脚本
chk_haproxy
}
track_interface { #追踪端口
eht0
}
notify_master "/etc/keepalived/notify.sh master" #通知脚本
notify_backup "/etc/keepalived/notify.sh backup"
notify_fault "/etc/keepalived/notify.sh fault"
}
vrrp_instance VI_2 {
state BACKUP #在A 上面是备，在B 上是主
interface eth0
virtual_router_id 51
priority 90
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.83.200/24 dev eth0 label eth0:1
}
track_scripts {
chk_haproxy
}
track_interface {
eth0
}
}
为keepalived提供脚本服务
#!/bin/bash
#Author: MageEdu <linuxedu@foxmail.com> #脚本出处
#description: An ample of notify script
vip=192.168.83.100
contact=‘root@localhost‘
notify() {
mailsubject="`hostname` to be $1: $vip floating"
mailbody="`date ‘+%F %H:%M:%S‘`: vrrp transition, `hostname` changed to be $1"
echo$mailbody | mail -s "$mailsubject"$contact
}
case"$1"in
master)
notify master
/etc/rc.d/init.d/haproxystart
exit0
;;
backup)
notify backup
/etc/rc.d/init.d/haproxystop
exit0
;;
fault)
notify fault
/etc/rc.d/init.d/haproxystop
exit0
;;
*)
echo‘Usage: `basename $0` {master|backup|fault}‘
exit1
;;
esac
配置haproxy B
因为haproxy A 和haproxy B 配置文件相同，所以发送一份即可
[root@90sec /]#scp /etc/haproxy/haproxy.cfg 192.168.83.133:/etc/haproxy/haproxy.cfg
配置heepalived
! Configuration File for keepalived
global_defs {
notification_email {
8888@126.com
}
notification_email_from root@localhost
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id LVS_DEVEL
}
vrrp_scrip chk_haproxy {
script "killall -0 haproxy"
interval 1
weight 2
}
vrrp_instance VI_1 {
state BACKUP
interface eth0
virtual_router_id 200
priority 90
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.83.100 dev eth0 label eth0:0
}
track_scripts {
chk_haproxy
}
track_interface {
eht0
}
}
vrrp_instance VI_2 {
state MASTER
interface eth0
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.83.200/24 dev eth0 label eth0:1
}
track_scripts {
chk_haproxy
}
track_interface {
eht0
}
notify_master "/etc/keepalived/notify.sh master"
notify_backup "/etc/keepalived/notify.sh backup"
notify_fault "/etc/keepalived/notify.sh fault"
}
注意：
notify_master "/etc/keepalived/notify.sh master"notify_backup "/etc/keepalived/notify.sh backup"notify_fault "/etc/keepalived/notify.sh fault"
3个状态分别要执行的脚本，只能放在 MASTER中，原因是：因为是互为主从，每个主的都会有个另外一个主的从，如果
把这 “3个状态执行脚本” 写入到从的区域中，那么另外一个主的从状态就会执行这个脚本，因为就会停掉所要高可用的
程序，这就造成了，两个VIP全部转移到其中一个服务器上去。
keepalived提供脚本服务相同，所以只需修改VIP 地址即可。日志配置方式也相同，参照上面即可。
四、测试keeplived功能
二个节点服务正常时
关闭haproxy A 上的keepalived看VIP 是否漂移
五、配置后端web服务
为web1 静态配置，并上传一张图片
为web2动态配置
# yum install -y php php-mysql
# vim /var/www/html/index.php
<h1>WebCome to WEB2</h1>
<?php
phpinfo();
?>
# service httpd start
Starting httpd: [ OK ]
本文出自 “断了的军刀” 博客，请务必保留此出处http://90sec.blog.51cto.com/7404127/1558170
keepalived + haproxy 实现web的高可用负载均衡