HAproxy 代理技术原理

来源：互联网发布：系统之家windows vista 编辑：程序博客网时间：2024/05/16 07:35

本文转载自: http://www.cnblogs.com/Bozh/p/4019607.html

1.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

2. Features

1.免费
2.能够做到4层以上代理
3.高性能
4.高稳定性

3. 使用案例

淘宝CDN(HTTP反向代理)

4. 测试

4.1 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:      500Time taken for tests:   32.562 secondsComplete requests:      100000Failed requests:        0Write errors:           0Total transferred:      36606588 bytesHTML transferred:       0 bytesRequests 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:      500Time taken for tests:   36.539 secondsComplete requests:      100000Failed requests:        0Write errors:           0Total transferred:      38600000 bytesHTML transferred:       0 bytesRequests 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

4.2 对比Nginx

NameNginxHAproxyHTTP代理性能910TCP 代理性能010稳定性1010转发规则107HTTP代理性能910平滑升级108

4.3 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                     Backendcurl |----------------->|                          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\r\nDate: 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\r\nDate: 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    ..

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