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下文给大家带来HAproxy+Keepalived负载均衡-高可用web站详细流程介绍，希望能够给大家在实际运用中带来一定的帮助，负载均衡涉及的东西比较多，理论也不多，网上有很多书籍，今天我们就用创新互联在行业内累计的经验来做一个解答。
haproxy+keepalived负载均衡高可用web站
OS | IP | 子网掩码 | 路由网关 |
Centos6.6 HAproxy Keepalived | Eth0:192.168.26.210 | 255.255.252.0 | 192.168.25.3 |
VIP:192.168.27.210 | |||
Centos6.6 HAporxy Keepalived | Eth0:192.168.26.211 | 255.255.252.0 | 192.168.25.3 |
VIP:192.168.27.210 | |||
Centos6.6(WEB) | Eth0:192.168.26.212 | 255.255.252.0 | 192.168.25.3 |
Centos6.6(WEB) | Eth0:192.168.26.218 | 255.255.252.0 | 192.168.25.3 |
1、安装Apache服务192.168.26.212和192.168.26.218：（yum install httpd –y）略启动
启动Apache，分别在两台云服务器上创建WEB页并确保网络能正常访问：
2、安装HAproxy:192.168.26.210和192.168.26.211：
Yum install –y haproxy
编辑配置文件：vim /etc/haproxy/haproxy.cfg
#---------------------------------------------------------------------
# Example configuration for a possible web application. See the
# full configuration options online.
#
# http://haproxy.1wt.eu/download/1.4/doc/configuration.txt
#
#---------------------------------------------------------------------
#---------------------------------------------------------------------
# Global settings
#---------------------------------------------------------------------
global
# to have these messages end up in /var/log/haproxy.log you will
# need to:
#
# 1) configure syslog to accept network log events. This is done
# by adding the '-r' option to the SYSLOGD_OPTIONS in
# /etc/sysconfig/syslog
#
# 2) configure local2 events to go to the /var/log/haproxy.log
# file. A line like the following can be added to
# /etc/sysconfig/syslog
#
# local2.* /var/log/haproxy.log
#
log 127.0.0.1 local2
chroot /var/lib/haproxy
pidfile /var/run/haproxy.pid
maxconn 4000
user haproxy
group haproxy
daemon
# 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
log global
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
#---------------------------------------------------------------------
#frontend main *:5000
# acl url_static path_beg -i /static /p_w_picpaths /javascript /stylesheets
# acl url_static path_end -i .jpg .gif .png .css .js
#
# use_backend static if url_static
# default_backend app
#
##---------------------------------------------------------------------
## static backend for serving up p_w_picpaths, stylesheets and such
##---------------------------------------------------------------------
#backend static
# balance roundrobin
# server static 127.0.0.1:4331 check
frontend websrv *:80
default_backend webservers
backend webservers
balance roundrobin
server node3 192.168.26.212:80 check
server node4 192.168.26.218:80 check
listen statick
bind *:1024
stats enable
stats uri /haadmin?stats
stats auth admin:admin
stats hide-version
stats admin if TRUE
192.168.26.211上配置文件也一样：因此我们直接SCP过去。
scp -p haproxy.cfg node2:/etc/haproxy/
启动两台服务器上的HAproxy服务。
安装keepalived:192.168.26.210和192.168.26.211
首先192.168.26.210配置：
Yum install –y keepalived
编辑配置文件：vim /etc/keepalived/keepalived.conf
配置文件：
! Configuration File for keepalived
global_defs {
notification_email {
acassen@firewall.loc
failover@firewall.loc
sysadmin@firewall.loc
}
notification_email_from jwenshan@163.com
smtp_server 192.168.200.1
smtp_connect_timeout 30
router_id LVS_DEVEL
}
vrrp_script chk_haproxy {
script "/etc/keepalived/chk.sh" //检查haproxy的脚本
interval 2 //每两秒检查一次
}
vrrp_instance VI_1 {
state BACKUP //定义为BACKUP节点
nopreempt //开启不抢占
interface eth0
virtual_router_id 51
priority 100 //开启了不抢占，所以此处优先级必须高于另一台
advert_int 1
authentication {
auth_type PASS
auth_pass jerry
}
virtual_ipaddress {
192.168.27.210 //配置VIP
}
track_script {
chk_haproxy //调用检查脚本
}
notify_backup "/etc/init.d/haproxy restart"
notify_fault "/etc/init.d/haproxy stop"
}
创建脚本文件：主要用于检测haproxy状态。
Vim /etc/keepalived/Chk.sh
#!/bin/bash
#
if [ $(ps -C haproxy --no-header | wc -l) -eq 0 ]; then
/etc/init.d/keepalived stop
Fi
启动Keepalived服务:
service keepalived start
192.168.26.211配置：
Yum install –y keepalived
编辑配置文件：Vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
notification_email {
acassen@firewall.loc
failover@firewall.loc
sysadmin@firewall.loc
}
notification_email_from jwenshan@163.com
smtp_server 192.168.200.1
smtp_connect_timeout 30
router_id LVS_DEVEL
}
vrrp_script chk_haproxy {
script "/etc/keepalived/chk.sh"
interval 2
}
vrrp_instance VI_1 {
state BACKUP
nopreempt
interface eth0
virtual_router_id 51
priority 99
advert_int 1
authentication {
auth_type PASS
auth_pass jerry
}
virtual_ipaddress {
192.168.27.210
}
track_script {
chk_haproxy
}
notify_backup "/etc/init.d/haproxy restart"
notify_fault "/etc/init.d/haproxy stop"
}
脚本文件：vim /etc/keepalived/chk.sh
#!/bin/bash
#
if [ $(ps -C haproxy --no-header | wc -l) -eq 0 ]; then
/etc/init.d/keepalived stop
Fi
启动Keepalived服务
Service keepalived start
测试VIP网络是否通畅：ping 192.168.27.210 –t
访问VIP网络：
Http://192.168.27.210
不断刷新浏览器观察显示结果
测试通过VIP访问后台监控页面：
访问成功。
测试高可用：
停掉192.168.26.210上Keepalived 观察结果：
Service keepalived stop
首先VIP网络出现波动：
再次访问VIP成功：
VIP已经转移动192.168.26.211上：
恢复192.168.26.210keepalived观察
：vip没有自动转移回192.168.26.210 这和我们的设置参数有关。
本试验keepalived配置中涉及几个重要参数，nopreempt state MASTER/ state BACKUP priority 可以更改其设置观察其变化，适应不同场景中的应用。
看了以上关于HAproxy+Keepalived负载均衡-高可用web站详细流程介绍，如果大家还有什么地方需要了解的可以在创新互联行业资讯里查找自己感兴趣的或者找我们的专业技术工程师解答的，创新互联技术工程师在行业内拥有十几年的经验了。