http://httpd.apache.org/docs/2.0/programs/ab.html
常用参数
-n 测试的请求次数
-c 并发请求个数
-k keep alive，所有的请求保持在同一个会话里面
ab -n 100 -c 10 http://www.yahoo.com/
Concurrency Level: 10 Time taken for tests: 1.889 seconds Complete requests: 100 Failed requests: 0 Write errors: 0 Total transferred: 1003100 bytes HTML transferred: 949000 bytes Requests per second: 52.94 [#/sec] (mean) Time per request: 188.883 [ms] (mean) Time per request: 18.888 [ms] (mean, across all concurrent requests) Transfer rate: 518.62 [Kbytes/sec] received Connection Times (ms) min mean[+/-sd] median max Connect: 57 59 1.7 59 64 Processing: 117 126 7.5 124 162 Waiting: 57 62 7.0 60 98 Total: 175 186 8.0 184 224 Percentage of the requests served within a certain time (ms) 50% 184 66% 186 75% 187 80% 188 90% 192 95% 203 98% 216 99% 224 100% 224 (longest request)
