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: 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
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 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 ...