基于Keepalived+Haproxy搭建四层负载均衡器-haproxy keepalived

一、前言
Haproxy是稳定、高性能、高可用性的负载均衡解决方案，支持HTTP及TCP代理后端服务器池，因支持强大灵活的7层acl规则，广泛作为HTTP 反向代理。本文则详细介绍如何利用它的四层交换与Keepalived实现一个负载均衡器，适用于Socket、ICE、Mail、Mysql、私有通讯等任意TCP服务。系统架构图如下：

二、平台环境

OS:Centos5.4(64X)
MASTER:192.168.0.20
BACKUP:192.168.0.21
VIP:192.168.0.100
Serivce Port:11231

三、平台安装配置

1、添加非本机IP邦定支持

#vi /etc/sysctl.conf
net.ipv4.ip_nonlocal_bind=1
#sysctl –p

2、配置平台日志支持

#vi /etc/syslog.conf
添加：
local3.* /var/log/haproxy.log
local0.* /var/log/haproxy.log

#vi /etc/sysconfig/syslog
修改：
SYSLOGD_OPTIONS="-r -m 0"
#/etc/init.d/syslog restart

3、关闭SELINUX

vi /etc/sysconfig/selinux
修改：
SELINUX=disabled
#setenforce 0

4、配置iptables，添加VRRP通讯支持

iptables -A INPUT -d 224.0.0.18 -j ACCEPT

5、Keepalived的安装、配置

#mkdir -p /home/install/keepalivedha
#cd /home/install/keepalivedha
#wget http://www.keepalived.org/software/keepalived-1.2.2.tar.gz
#tar zxvf keepalived-1.2.2.tar.gz
#cd keepalived-1.2.2
#./configure
#make && make install

#cp /usr/local/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/
#cp /usr/local/etc/sysconfig/keepalived /etc/sysconfig/
#mkdir /etc/keepalived
#cp /usr/local/etc/keepalived/keepalived.conf /etc/keepalived/
#cp /usr/local/sbin/keepalived /usr/sbin/

#vi /etc/keepalived/keepalived.conf

! Configuration File for keepalived
global_defs {
notification_email {
liutiansi@gmail.com
}
notification_email_from liutiansi@gmail.com
smtp_connect_timeout 3
smtp_server 127.0.0.1
router_id LVS_DEVEL
}
vrrp_script chk_haproxy {
script "killall -0 haproxy"
interval 2
weight 2
}
vrrp_instance VI_1 {
interface eth1
state MASTER # 从为BACKUP
priority 101 # 从为100
virtual_router_id 50 #路由ID，可通过#tcpdump vrrp查看。
garp_master_delay 1 #主从切换时间，单位为秒。
authentication {
auth_type PASS
auth_pass KJj23576hYgu23IP
}
track_interface {
eth0
eth1
}
virtual_ipaddress {
192.168.0.100
}
track_script {
chk_haproxy
}
#状态通知
notify_master "/etc/keepalived/Mailnotify.py master"
notify_backup "/etc/keepalived/Mailnotify.py backup"
notify_fault "/etc/keepalived/Mailnotify.py fault"
}

#p#

6、Haproxy的安装与配置

#cd /home/install/keepalivedha
#wget http://haproxy.1wt.eu/download/1.4/src/haproxy-1.4.11.tar.gz
#tar -zxvf haproxy-1.4.11.tar.gz
#cd haproxy-1.4.11
#make install
#mkdir -p /usr/local/haproxy/etc
#mkdir -p /usr/local/haproxy/sbin
#cp examples/haproxy.cfg /usr/local/haproxy/etc
#ln -s /usr/local/sbin/haproxy /usr/local/haproxy/sbin/haproxy

#vi /usr/local/haproxy/etc/haproxy.cfg

# this config needs haproxy-1.1.28 or haproxy-1.2.1
global
# log 127.0.0.1 local0
log 127.0.0.1 local1 notice
maxconn 5000
uid 99
gid 99
daemon
pidfile /usr/local/haproxy/haproxy.pid
defaults
log global
mode http
#option httplog
option dontlognull
retries 3
option redispatch
maxconn 2000
contimeout 5000
clitimeout 50000
srvtimeout 50000
listen ICE01 192.168.0.100:11231
mode tcp #配置TCP模式
maxconn 2000
balance roundrobin
server ice-192.168.0.128 192.168.0.128:11231 check inter 5000 fall 1 rise 2
server ice-192.168.0.129 192.168.0.129:11231 check inter 5000 fall 1 rise 2
server ice-192.168.0.130 192.168.0.130:11231 check inter 5000 fall 1 rise 2
server ice-192.168.0.131 192.168.0.131:11231 check inter 5000 fall 1 rise 2
server ice-192.168.0.132 192.168.0.132:11231 check inter 5000 fall 1 rise 2
server ice-192.168.0.34 192.168.0.34:11231 check inter 5000 fall 1 rise 2
srvtimeout 20000
listen stats_auth 192.168.0.20:80
# listen stats_auth 192.168.0.21:80 # backup config
stats enable
stats uri /admin-status #管理地址
stats auth admin:123456 #管理帐号:管理密码
stats admin if TRUE

7、邮件通知程序(python实现)

#vi /etc/keepalived/Mailnotify.py

#!/usr/local/bin/python
#coding: utf-8
from email.MIMEMultipart import MIMEMultipart
from email.MIMEText import MIMEText
from email.MIMEImage import MIMEImage
from email.header import Header
import sys
import smtplib
#---------------------------------------------------------------
# Name: Mailnotify.py
# Purpose: Mail notify to SA
# Author: Liutiansi
# Email: liutiansi@gamil.com
# Created: 2011/03/09
#--------------------------------------------------------------
strFrom = 'admin@domain.com'
strTo = 'liutiansi@gmail.com'
smtp_server='smtp.domain.com'
smtp_pass='123456'
if sys.argv[1]!="master" and sys.argv[1]!="backup" and sys.argv[1]!="fault":
sys.exit()
else:
notify_type=sys.argv[1]
mail_title='[紧急]负载均衡器邮件通知'
mail_body_plain=notify_type+'被激活，请做好应急处理。'
mail_body_html='<b><font color=red>'+notify_type+'被激活，请做好应急处理。</font></b>'
msgRoot = MIMEMultipart('related')
msgRoot['Subject'] =Header(mail_title,'utf-8')
msgRoot['From'] = strFrom
msgRoot['To'] = strTo
msgAlternative = MIMEMultipart('alternative')
msgRoot.attach(msgAlternative)
msgText = MIMEText(mail_body_plain, 'plain', 'utf-8')
msgAlternative.attach(msgText)
msgText = MIMEText(mail_body_html, 'html','utf-8')
msgAlternative.attach(msgText)
smtp = smtplib.SMTP()
smtp.connect(smtp_server)
smtp.login(smtp_user,smtp_pass)
smtp.sendmail(strFrom, strTo, msgRoot.as_string())
smtp.quit()

注：修改成系统python实际路径“#!/usr/local/bin/python”(第一行)

#chmod +x /etc/keepalived/Mailnotify.py

#/usr/local/haproxy/sbin/haproxy -f /usr/local/haproxy/etc/haproxy.cfg

#service keepalived start

8、查看VRRP通讯记录

#tcpdump vrrp

tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes
15:49:05.270017 IP 192.168.0.20 > VRRP.MCAST.NET: VRRPv2, Advertisement, vrid 50, prio 100, authtype simple, intvl 1s, length 20

四、Haproxy界面
访问http://192.168.0.20/admin-status，输入帐号admin密码123456进入管理监控平台。

haproxy-1.4.9以后版本最大的亮点是添加了手工启用/禁用功能，对升级变更应用时非常有用。
五、邮件通知