web压力测试

#wget http://home.tiscali.cz/~cz210552/distfiles/webbench-1.5.tar.gz#tarzxvfwebbench-1.5.tar.gz #cd webbench-1.5#make&& make install

# webbench-c 200-t 60 http://down.chinaz.com/index.php[/code]参数解释：-c为并发数，-t为时间(秒) 
Webbench - Simple Web Benchmark 1.5Copyright(c) Radim Kolar 1997-2004, GPL Open SourceSoftware.
Benchmarking:GEThttp://down.chinaz.com/index.php200 clients, running 60 sec.
Speed=1454 pages/min,2153340 bytes/sec.
Requests:1454 susceed,0 failed.
当并发200时，网站访问速度正常
并发800时
#webbench-c 800-t 60 http://down.chinaz.com/index.php Webbench - Simple Web Benchmark 1.5Copyright(c) Radim Kolar 1997-2004, GPL Open SourceSoftware.
Benchmarking:GEThttp://down.chinaz.com/index.php800 clients, running 60 sec.
Speed=1194 pages/min,2057881 bytes/sec.
Requests:1185 susceed,9 failed.
当并发连接为800时，网站访问速度稍慢
并发1600时
#webbench-c 1600-t 60 http://down.chinaz.com/index.php Webbench - Simple Web Benchmark 1.5Copyright(c) Radim Kolar 1997-2004, GPL Open SourceSoftware.
Benchmarking:GEThttp://down.chinaz.com/index.php1600 clients, running 60 sec.
Speed=1256 pages/min,1983506 bytes/sec.
Requests:1183 susceed,73 failed.
当并发连接为1600时，网站访问速度便非常慢了
并发2000时
#webbench-c 2000-t 60 http://down.chinaz.com/index.php Webbench - Simple Web Benchmark 1.5Copyright(c) Radim Kolar 1997-2004, GPL Open SourceSoftware.
Benchmarking:GEThttp://down.chinaz.com/index.php2000 clients, running 60 sec.
Speed=2154 pages/min,1968292 bytes/sec.
Requests:2076 susceed,78 failed.
当并发2000时，网站便出现"502 Bad Gateway"，由此可见web服务器已无法再处理用户访问请求
总结：
1、压力测试工作应该放到产品上线之前，而不是上线以后
2、测试时尽量跨公网进行，而不是内网
3、测试时并发应当由小逐渐加大，比如并发100时观察一下网站负载是多少、打开是否流程，并发200时又是多少、网站打开缓慢时并发是多少、网站打不开时并发又是多少
4、 应尽量进行单元测试，如B2C网站可以着重测试购物车、推广页面等，因为这些页面占整个网站访问量比重较大
 http://down.chinaz.com/server/201202/1671_1.htm