HAproxy 技术分享
简介
HAProxy是一款提供高可用性、负载均衡以及基于TCP（第四层）和HTTP（第七层）应用的代理软件
Features
1.免费
2.能够做到4层以上代理
3.高性能
4.高稳定性
使用案例
淘宝CDN(HTTP反向代理)
测试:
HTTP代理 ab -i -c 500 -n 100000
| --- node 8910 URL = /
HAproxy| --- node 8911 URL = /
| --- node 8912 URL = /
| --- node 8913 /test/ (reqisetbe ^[^ ]* /(test|uri)/ server_uri_route) #按照规则转发
####### haproxy : (单独由haproxy进行均衡负载)
Concurrency Level: 500
Time taken for tests: 32.562 seconds
Complete requests: 100000
Failed requests: 0
Write errors: 0
Total transferred: 36606588 bytes
HTML transferred: 0 bytes
Requests per second: 3071.02 [#/sec] (mean)
Time per request: 162.812 [ms] (mean)
Time per request: 0.326 [ms] (mean, across all concurrent requests)
Transfer rate: 1097.85 [Kbytes/sec] received
####### nginx : (单独由nginx进行均衡负载)
Concurrency Level: 500
Time taken for tests: 36.539 seconds
Complete requests: 100000
Failed requests: 0
Write errors: 0
Total transferred: 38600000 bytes
HTML transferred: 0 bytes
Requests per second: 2736.82 [#/sec] (mean)
Time per request: 182.694 [ms] (mean)
Time per request: 0.365 [ms] (mean, across all concurrent requests)
Transfer rate: 1031.65 [Kbytes/sec] received
对比Nginx
| Name | Nginx | HAproxy |
|---|---|---|
| HTTP代理性能 | 9 | 10 |
| TCP 代理性能 | 0 | 10 |
| 稳定性 | 10 | 10 |
| 转发规则 | 10 | 7 |
| HTTP代理性能 | 9 | 10 |
| 平滑升级 | 10 | 8 |
原理 epoll 转发
验证 转发方式为如下
通过TCP代理请求 www.baidu.com
client HAProxy Backend
curl |----------------->|
accept(client)
recvfrom(client)
sendto(Backent)
|-------->|
dowith(HAProxy)
|<--------|
recvfrom(Backend)
sendto(Client)
|<-----------------|
strace 查看系统调用
zhangbo3@vm-222:/etc/haproxy$ sudo strace -p 7876
epoll_wait(0, {{EPOLLIN, {u32=5, u64=5}}}, 7, 1000) = 1
*** (事件循环，监听连接事件)
accept(5, {
sa_family=AF_INET,
sin_port=htons(56479),
sin_addr=inet_addr("127.0.0.1")
}, [16]) = 1
*** (来自客户端[127.0.0.1]的请求, 端口56479[随机端口])
fcntl(1, F_SETFL, O_RDONLY|O_NONBLOCK) = 0
*** (设置连接socket为非阻塞)
setsockopt(1, SOL_TCP, TCP_NODELAY, [1], 4) = 0
*** (设置TCP连接为 NODELAY, 禁止Nagle算法)
accept(5, 0x7fff8da2d7a0, [128]) = -1 EAGAIN
(Resource temporarily unavailable)
*** (再次去accept连接失败，因为accept被循环包裹，需要返回 EAGAIN才break)
recvfrom(1, "GET HTTP://www.baidu.com HTTP/1."..., 8192) = 212
*** (收到来自客户端的请求 curl -x 127.0.0.1:1180 www.baidu.com)
recvfrom(1, 0x2560ac4, 7980, 0, 0, 0) = -1 EAGAIN
(Resource temporarily unavailable)
*** (返回EAGAIN后break,表示收到完整的TCP数据, 开始处理请求数据)
epoll_ctl(0, EPOLL_CTL_ADD, 1, {EPOLLIN, {u32=1, u64=1}}) = 0
*** (将来自客户端的socket加入epoll监听队列)
socket(PF_INET, SOCK_STREAM, IPPROTO_TCP) = 2
fcntl(2, F_SETFL, O_RDONLY|O_NONBLOCK) = 0
setsockopt(2, SOL_TCP, TCP_NODELAY, [1], 4) = 0
connect(2, {
sa_family=AF_INET,
sin_port=htons(8912),
sin_addr=inet_addr("127.0.0.1")
}, 16) = -1 EINPROGRESS (Operation now in progress)
*** (创建到backend的socket连接,这里backend配置为8912)
*** (server server3 127.0.0.1:8912)
sendto(2, "GET HTTP://www.baidu.com HTTP/1."...,
212, MSG_DONTWAIT|MSG_NOSIGNAL, NULL, 0) = 212
*** (发送数据到backend)
epoll_wait(0, {}, 7, 0) = 0
*** (继续进入epoll_wait,等待来自backend的数据返回)
gettimeofday({1413020002, 322710}, NULL) = 0
recvfrom(2, 0x255c960, 16384, 0, 0, 0) = -1 EAGAIN
(Resource temporarily unavailable)
*** (Backend数据来了)
epoll_ctl(0, EPOLL_CTL_ADD, 2, {EPOLLIN, {u32=2, u64=2}}) = 0
epoll_wait(0, {{EPOLLIN, {u32=2, u64=2}}}, 7, 1000) = 1
gettimeofday({1413020003, 308930}, NULL) = 0
recvfrom(2, "HTTP/1.1 200 OK
Date: Sat, 11 O"...,16384) = 2896
*** (backend 返回 HTTP 200, 这是标准HTTP协议头)
recvfrom(2, 0x255d4b0, 13488, 0, 0, 0) = -1 EAGAIN
(Resource temporarily unavailable)
sendto(1, "HTTP/1.1 200 OK
Date: Sat, 11 O"...) = 2896
*** (将backend返回的数据发送到front end)
epoll_wait(0, {{EPOLLIN, {u32=2, u64=2}}}, 7, 1000) = 1
*** (继续进入epoll_wait)
gettimeofday({1413020003, 309695}, NULL) = 0
*** (客户端连接超时，关闭连接)
shutdown(2, 1 /* send */) = 0
close(2) = 0
shutdown(1, 1 /* send */) = 0
close(1) = 0
验证单进程模型 -> 查看线程数
cat /proc/7878/status
Name: haproxy
State: S (sleeping)
...
Threads: 1
SigQ: 0/15594
SigPnd: 0000000000000000
ShdPnd: 0000000000000000
...