前言* 随着負載均衡器的成熟，人們熟知的軟體負載均衡如LVS、HAProxy，各方面性能不亞于硬體負載均衡，HAProxy提供高可用性、負載均衡以及基于TCP和HTTP應用的代理，支援虛拟主機，它是免費、快速并且可靠的一種解決方案。
HAProxy特别适用于那些負載特大的web站點，這些站點通常又需要會話保持或七層處理。
我們平時用的負載均衡LVS是基于四層，新型的大型網際網路公司也在采用HAProxy，了解了haproxy大并發、七層應用等特點，那今天我們來研究一下HAProxy+Keepalived基于七層負載高可用負載均衡的配置。
一、系統環境：
系統版本：CentOS6.0 x86_64
HAProxy版本：1.4.21
Keepalived版本:1.2.1
Nginx版本：1.2.2
MASTER_IP:192.168.0.130
BACKUP_IP:192.168.0.131
VIP:192.168.0.133
WEB_1:192.168.0.134
WEB_2:192.168.0.135
二、HAProxy安裝：
1）首先安裝192.168.0.130上安裝：
下載下傳最新穩定版本:1.4.21
cd /usr/src ;wget http://haproxy.1wt.eu/download/1.4/src/haproxy-1.4.21.tar.gz
tar xzf haproxy-1.4.21.tar.gz &&cd haproxy-1.4.21 &&make TARGET=linux26 PREFIX=/usr/local/haproxy &&make install PREFIX=/usr/local/haproxy
安裝完畢，在/usr/local/haproxy/目錄下會看到三個目錄：doc、sbin、share
2) 接下來配置HAProxy。
cd /usr/local/haproxy ;mkdir -p etc/
然後在/usr/local/haproxy/etc/下建立haproxy.cfg檔案，這裡拷貝haproxy配置檔案：
global
log 127.0.0.1 local0
maxconn 65535
chroot /usr/local/haproxy
uid 99
gid 99
daemon
nbproc 8
pidfile /usr/local/haproxy/haproxy.pid
defaults
log 127.0.0.1 local3
mode http
option httplog
option httpclose
option dontlognull
option forwardfor
option redispatch
retries 2
maxconn 65535
balance source
stats uri /web-status
contimeout 5000
clitimeout 50000
srvtimeout 50000
listen chinaapp.sinaapp.com
bind *:80
mode http
option httplog
log global
option httpchk HEAD /index.html HTTP/1.0
server web1 192.168.0.134:80 weight 5 check inter 2000 rise 2 fall 3
server web2 192.168.0.135:80 weight 5 check inter 2000 rise 2 fall 3
然後啟動haproxy，如下執行啟動指令：
/usr/local/haproxy/sbin/haproxy -f /usr/local/haproxy/etc/haproxy.cfg
[WARNING] 217/202150 (2857) : Proxy 'chinaapp.sinaapp.com': in multi-process mode, stats will be limited to process assigned to the current request.
會提示如上資訊，nbproc程序如果設定為1則不會提示，如果想去掉這個提示可以修改編譯檔案即可。 在源碼配置src/cfgparse.c找到如下行
if (nbproc > 1) {
if (curproxy->uri_auth) {
- Warning("Proxy '%s': in multi-process mode, stats will be limited to process assigned to the current request.\n",
+ Warning("Proxy '%s': in multi-process mode, stats will be limited to the process assigned to the current request.\n",
調整nbproc > 1數值即可。
三、安裝Keepalived:
cd /usr/src ;
wget http://www.keepalived.org/software/keepalived-1.2.1.tar.gz
tar xzf keepalived-1.2.1.tar.gz
cd keepalived-1.2.1 &&
./configure –with-kernel-dir=/usr/src/kernels/2.6.32-71.el6.x86_64/ &&make &&make install
DIR=/usr/local/ ;cp $DIR/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/ && cp $DIR/etc/sysconfig/keepalived /etc/sysconfig/ && mkdir -p /etc/keepalived && cp $DIR/sbin/keepalived /usr/sbin/
四、配置keepalived:
! Configuration File for keepalived
global_defs {
notification_email {
}
notification_email_from [email protected]
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id LVS_DEVEL
vrrp_script chk_haproxy {
script "/data/sh/check_haproxy.sh"
interval 2
weight 2
# VIP1
vrrp_instance VI_1 {
state BACKUP
interface eth0
lvs_sync_daemon_inteface eth0
virtual_router_id 151
priority 100
advert_int 5
nopreempt
authentication {
auth_typePASS
auth_pass 2222
}
virtual_ipaddress {
192.168.0.133
track_script {
chk_haproxy
}
五、建立haproxy腳本：
設定可執行權限chmod +x check_haproxy.sh，内容如下：
#!/bin/bash
#auto check haprox process
#2012-8-12 wugk
killall -0 haproxy
if
[[ $? -ne 0 ]];then
/etc/init.d/keepalived stop
fi
BACKUP同樣如上配置haproxy、keepalived，配置完修改優先級為90即可，然後啟動。
六、測試haproxy+keepalived：
如圖當手動kill 掉131的haproxy程序後，130的keepalived背景日志顯示如下，并且通路VIP 192.168.0.133 正常通路：
<a target="_blank" href="http://blog.51cto.com/attachment/201208/180520314.png"></a>
通路haproxy status如下圖：
<a target="_blank" href="http://blog.51cto.com/attachment/201208/181453164.png"></a>
本文轉自 wgkgood 51CTO部落格，原文連結:http://blog.51cto.com/wgkgood/961544
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