对haproxy代理流程的数据进行抓包分析

对haproxy代理流程的数据进行抓包分析




各模块名称以及作用

haproxy.cfg文件配置如下

global
maxconn 20480
log 127.0.0.1 local3
chroot /var/haproxy
uid 99
gid 99
daemon
nbproc 1
pidfile /var/run/haproxy.pid
ulimit-n 65535
defaults
log global
mode http
maxconn 20480
option httplog
option httpclose
option dontlognull
option forwardfor
option redispatch
option abortonclose
stats refresh 30
retries 3
balance roundrobin
contimeout 5000
clitimeout 50000
srvtimeout 50000
timeout check 2000

listen  admin_status
bind 0.0.0.0:65532
mode http
log 127.0.0.1 local3 err
stats refresh 5s
stats uri /admin?stats
stats realm itnihao\ itnihao
stats auth admin:admin
stats auth admin1:admin1
stats hide-version
stats admin if TRUE
errorfile 403 /etc/haproxy/errorfiles/403.http
errorfile 500 /etc/haproxy/errorfiles/500.http
errorfile 502 /etc/haproxy/errorfiles/502.http
errorfile 503 /etc/haproxy/errorfiles/503.http
errorfile 504 /etc/haproxy/errorfiles/504.http

capture request  header Host           len 40
capture request  header Content-Length len 10
capture request  header Referer        len 200
capture response header Server         len 40
capture response header Content-Length len 10
capture response header Cache-Control  len 8
listen  site_status
bind 0.0.0.0:1081
mode http
log 127.0.0.1 local3 err
monitor-uri /site_status
acl site_dead nbsrv(server_web) lt 2
monitor fail if site_dead

frontend  http_80_in
bind 0.0.0.0:80
mode http
log global
option httplog
option httpclose
option forwardfor
acl itnihao_web hdr_reg(host) -i ^(www.itnihao.cn|ww1.itnihao.cn)$
acl itnihao_blog hdr_dom(host) -i blog.itnihao.cn
use_backend  server_web  if itnihao_web
use_backend  server_blog if itnihao_blog
default_backend server_bbs

backend server_web
mode http
balance roundrobin
cookie SERVERID
option httpchk GET /index.html
server web1 192.168.16.2:80 cookie web1 check inter 1500 rise 3 fall 3 weight 1
server web2 192.168.16.3:80 cookie web2 check inter 1500 rise 3 fall 3 weight 2

backend server_bbs
mode http
balance roundrobin
cookie SERVERID
option httpchk GET /index.html
server bbs1 192.168.16.2:80 cookie bbs1 check inter 1500 rise 3 fall 3 weight 1
server bbs2 192.168.16.3:80 cookie bbs2 check inter 1500 rise 3 fall 3 weight 2

客户端192.168.16.90访问http://ww1.itnihao.cn



Haproxy的日志如下，可以看到，负载均衡到web2和web1上面去了



详细日志如下所示
Jul 2 04:09:19 localhost haproxy[30015]: 192.168.16.90:4329 [02/Jul/2012:04:09:19.876] http_80_in server_web/web2 31/0/10/0/44 200 271 - - ---- 0/0/0/0/0 0/0 "GET / HTTP/1.1"
Jul 2 04:09:19 localhost haproxy[30015]: 192.168.16.90:4329 [02/Jul/2012:04:09:19.876] http_80_in server_web/web2 31/0/10/0/44 200 271 - - ---- 0/0/0/0/0 0/0 "GET / HTTP/1.1"
Jul 2 04:09:19 localhost haproxy[30015]: 192.168.16.90:4329 [02/Jul/2012:04:09:19.876] http_80_in server_web/web2 31/0/10/0/44 200 271 - - ---- 0/0/0/0/0 0/0 "GET / HTTP/1.1"
Jul 2 04:09:19 localhost haproxy[30015]: 192.168.16.90:4329 [02/Jul/2012:04:09:19.876] http_80_in server_web/web2 31/0/10/0/44 200 271 - - ---- 0/0/0/0/0 0/0 "GET / HTTP/1.1"
Jul 2 04:09:19 localhost haproxy[30015]: 192.168.16.90:4329 [02/Jul/2012:04:09:19.876] http_80_in server_web/web2 31/0/10/0/44 200 271 - - ---- 0/0/0/0/0 0/0 "GET / HTTP/1.1"
Jul 2 04:09:19 localhost haproxy[30015]: 192.168.16.90:4329 [02/Jul/2012:04:09:19.876] http_80_in server_web/web2 31/0/10/0/44 200 271 - - ---- 0/0/0/0/0 0/0 "GET / HTTP/1.1"
Jul 2 04:09:22 localhost haproxy[30015]: 192.168.16.90:4330 [02/Jul/2012:04:09:21.985] http_80_in server_web/web1 6/0/35/27/70 200 271 - - ---- 0/0/0/0/0 0/0 "GET / HTTP/1.1"
Jul 2 04:09:22 localhost haproxy[30015]: 192.168.16.90:4330 [02/Jul/2012:04:09:21.985] http_80_in server_web/web1 6/0/35/27/70 200 271 - - ---- 0/0/0/0/0 0/0 "GET / HTTP/1.1"
Jul 2 04:09:22 localhost haproxy[30015]: 192.168.16.90:4330 [02/Jul/2012:04:09:21.985] http_80_in server_web/web1 6/0/35/27/70 200 271 - - ---- 0/0/0/0/0 0/0 "GET / HTTP/1.1"
Jul 2 04:09:22 localhost haproxy[30015]: 192.168.16.90:4330 [02/Jul/2012:04:09:21.985] http_80_in server_web/web1 6/0/35/27/70 200 271 - - ---- 0/0/0/0/0 0/0 "GET / HTTP/1.1"
Jul 2 04:09:22 localhost haproxy[30015]: 192.168.16.90:4330 [02/Jul/2012:04:09:21.985] http_80_in server_web/web1 6/0/35/27/70 200 271 - - ---- 0/0/0/0/0 0/0 "GET / HTTP/1.1"
Jul 2 04:09:22 localhost haproxy[30015]: 192.168.16.90:4330 [02/Jul/2012:04:09:21.985] http_80_in server_web/web1 6/0/35/27/70 200 271 - - ---- 0/0/0/0/0 0/0 "GET / HTTP/1.1"
在haproxy 192.168.16.22上面抓包【勘误】
（2012-07-31修改此处，原文是“在web2上面抓包”，其实下面的数据是在3台机器上面的，即haproxy，web1，web2上面抓包的结果分析）




查看抓包数据如下



客户端192.168.16.90首先向ww1.itnihao.cn(192.168.16.22)发送请求，haproxy代理服务器192.168.16.22收到请求，根据以下的配置文件的则，将请求用调度算法roundrobin转发给后端web2，即192.168.16.3
frontend http_80_in
bind 0.0.0.0:80
mode http
log global
option httplog
option httpclose
option forwardfor
acl itnihao_web hdr_reg(host) -i ^(www.itnihao.cn|ww1.itnihao.cn)$
use_backend server_web if itnihao_web
backend server_web
mode http
balance roundrobin
cookie SERVERID
option httpchk GET /index.html
server web1 192.168.16.2:80 cookie web1 check inter 1500 rise 3 fall 3 weight 1
server web2 192.168.16.3:80 cookie web2 check inter 1500 rise 3 fall 3 weight 2




可以看到，haproxy会将请求的www.itnihao.cn转发给192.168.16.3，且标记客户端的ip，如192.168.16.3有多个基于域名的虚拟主机，可以通过请求的域名来正确的识别到虚拟主机，这点无需担心
ip转发的选项是option forwardfor 转发过来的ip，如此，则端服务器可以获取到真实的客户端ip，



192.168.16.3响应haproxy的请求，将数据index.html提供给haproxy192.168.16.22



代理过程完成，192.168.16.22将index.html数据发送给用户端，用户端192.168.16.90完成此次的服务器请求，对用户来说是完全透明的。

同理，代理将请求转发给192.168.16.2，叙述过程不再重复，从抓包数据的结果可以看到












以上内容为本人对haproxy的一些理解，如有误差，欢迎各位指正！
另外附录两篇对haproxy代码的分析链接

http://blog.csdn.net/chen_jianjian/article/details/7303909
haproxy工作流程分析
http://blog.csdn.net/chen_jianjian/article/details/7317758
haproxy初始化函数分析

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