ab是apache自带的一个很好用的压力测试工具，当安装完apache的时候，就可以在bin下面找到ab
1 我们可以模拟100个并发用户，对一个页面发送1000个请求
./ab -n1000 -c100 http://www.a.com/a.html
其中-n代表请求数，-c代表并发数
返回结果:
##首先是apache的版本信息
This is ApacheBench, Version 2.3
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/
Benchmarking www.a.com (be patient)
Server Software: Apache/2.2.19 ##apache版本
Server Hostname: www.a.com ##请求的机子
Server Port: 80 ##请求端口
Document Path: /a.html
Document Length: 25 bytes ##页面长度
Concurrency Level: 100 ##并发数
Time taken for tests: 0.273 seconds ##共使用了多少时间
Complete requests: 1000 ##请求数
Failed requests: 0 ##失败请求
Write errors: 0
Total transferred: 275000 bytes ##总共传输字节数，包含http的头信息等
HTML transferred: 25000 bytes ##html字节数，实际的页面传递字节数
Requests per second: 3661.60 [#/sec] (mean) ##每秒多少请求，这个是非常重要的参数数值，服务器的吞吐量
Time per request: 27.310 [ms] (mean) ##用户平均请求等待时间
Time per request: 0.273 [ms] (mean, across all concurrent requests) ##服务器平均处理时间，也就是服务器吞吐量的倒数
Transfer rate: 983.34 [Kbytes/sec] received ##每秒获取的数据长度
Connection Times (ms)
min mean[+/-sd] median max
Connect: 0 1 2.3 0 16
Processing: 6 25 3.2 25 32
Waiting: 5 24 3.2 25 32
Total: 6 25 4.0 25 48
Percentage of the requests served within a certain time (ms)
50% 25 ## 50%的请求在25ms内返回
66% 26 ## 60%的请求在26ms内返回
75% 26
80% 26
90% 27
95% 31
98% 38
99% 43
100% 48 (longest request)
以下测试我公司的营销服务器
[root@rfyy-02 bin]# ./ab -c500 -n3000 http://27.17.x.x:8899/index.html
This is ApacheBench, Version 2.3 <$Revision: 655654 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/
Benchmarking 27.17.x.x (be patient)
Completed 300 requests
Completed 600 requests
Completed 900 requests
Completed 1200 requests
Completed 1500 requests
Completed 1800 requests
Completed 2100 requests
Completed 2400 requests
Completed 2700 requests
Completed 3000 requests
Finished 3000 requests
Server Software: Microsoft-IIS/7.0
Server Hostname: 27.17.x.x
Server Port: 8899
Document Path: /index.html
Document Length: 1163 bytes
Concurrency Level: 500
Time taken for tests: 26.305 seconds
Complete requests: 3000
Failed requests: 0
Write errors: 0
Non-2xx responses: 3000
Total transferred: 4026000 bytes
HTML transferred: 3489000 bytes
Requests per second: 114.04 [#/sec] (mean)
Time per request: 4384.240 [ms] (mean)
Time per request: 8.768 [ms] (mean, across all concurrent requests)
Transfer rate: 149.46 [Kbytes/sec] received
Connection Times (ms)
min mean[+/-sd] median max
Connect: 40 1785 2496.9 1024 19477
Processing: 98 1164 1474.8 905 16456
Waiting: 95 1163 1464.5 905 15373
Total: 284 2949 2979.1 2161 20495
Percentage of the requests served within a certain time (ms)
50% 2161
66% 2378
75% 4071
80% 4615
90% 5436
95% 9873
98% 11647
99% 17183
100% 20495 (longest request)