压力测试工具之ab

1 ab命令原理
Apache的ab命令模拟多线程并发请求，测试服务器负载压力，也可以测试nginx、lighthttp、IIS等其它Web服务器的压力。
ab命令对发出负载的计算机要求很低，既不会占用很多CPU，也不会占用太多的内存，但却会给目标服务器造成巨大的负载，因此是某些DDOS攻击之必备良药，老少皆宜。自己使用也须谨慎。否则一次上太多的负载，造成目标服务器直接因内存耗光死机，而不得不硬重启，得不偿失。

在带宽不足的情况下，最好是本机进行测试，建议使用内网的另一台或者多台服务器通过内网进行测试，这样得出的数据，准确度会高很多。远程对web服务器进行压力测试，往往效果不理想（因为网络延时过大或带宽不足）

2 运行
A 100个并发，总请求数 500

ab -c 100 -n 500 http://127.0.0.1/phpinfo.phpThis is ApacheBench, Version 2.3 <$Revision: 1604373 $>Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/Licensed to The Apache Software Foundation, http://www.apache.org/Benchmarking 127.0.0.1 (be patient)Completed 100 requestsCompleted 200 requestsCompleted 300 requestsCompleted 400 requestsCompleted 500 requestsFinished 500 requestsServer Software:        Apache/2.4.10Server Hostname:        127.0.0.1Server Port:            80Document Path:          /phpinfo.phpDocument Length:        66005 bytes  HTTP响应数据的正文长度Concurrency Level:      100Time taken for tests:   1.759 secondsComplete requests:      500Failed requests:        78   (Connect: 0, Receive: 0, Length: 78, Exceptions: 0)Total transferred:      33096996 bytesHTML transferred:       33002496 bytesRequests per second:    284.30 [#/sec] (mean)Time per request:       351.739 [ms] (mean)Time per request:       3.517 [ms] (mean, across all concurrent requests)Transfer rate:          18377.98 [Kbytes/sec] receivedConnection Times (ms)              min  mean[+/-sd] median   maxConnect:        0    0   0.8      0      12Processing:     3  316 447.9    112    1423Waiting:        1  311 449.2    100    1423Total:          3  316 448.0    112    1435Percentage of the requests served within a certain time (ms)  50%    112  66%    260  75%    276  80%    345  90%   1236  95%   1297  98%   1339  99%   1358 100%   1435 (longest request)

B 在60秒内发请求，一次100个请求。

ab -c 100 -t 60 http://127.0.0.1/phpinfo.phpThis is ApacheBench, Version 2.3 <$Revision: 1604373 $>Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/Licensed to The Apache Software Foundation, http://www.apache.org/Benchmarking 127.0.0.1 (be patient)Completed 5000 requestsCompleted 10000 requestsFinished 10525 requestsServer Software:        Apache/2.4.10Server Hostname:        127.0.0.1Server Port:            80Document Path:          /phpinfo.phpDocument Length:        66005 bytesConcurrency Level:      100Time taken for tests:   60.000 secondsComplete requests:      10525Failed requests:        1115   (Connect: 0, Receive: 0, Length: 1115, Exceptions: 0)Total transferred:      696690603 bytesHTML transferred:       694701378 bytesRequests per second:    175.42 [#/sec] (mean)Time per request:       570.076 [ms] (mean)Time per request:       5.701 [ms] (mean, across all concurrent requests)Transfer rate:          11339.28 [Kbytes/sec] receivedConnection Times (ms)              min  mean[+/-sd] median   maxConnect:        0    0   0.9      0      34Processing:     0  567 1689.7    273   18692Waiting:        0  561 1689.3    270   18692Total:          0  567 1689.7    274   18693Percentage of the requests served within a certain time (ms)  50%    273  66%    295  75%    338  80%    401  90%    657  95%   1305  98%   4499  99%   7287 100%  18693 (longest request)

C 在url中带参数，p.txt 是和ab.exe在一个目录，p.txt 中可以写参数，如 p=wdp&fq=78

ab -t 60 -c 100 -T "text/plain" -p p.txt http://127.0.0.1/phpinfo.php

3 帮助

ab -hUsage: ab [options] [http://]hostname[:port]/pathOptions are:    -n requests     Number of requests to perform    -c concurrency  Number of multiple requests to make at a time    -t timelimit    Seconds to max. to spend on benchmarking                    This implies -n 50000    -s timeout      Seconds to max. wait for each response                    Default is 30 seconds    -b windowsize   Size of TCP send/receive buffer, in bytes    -B address      Address to bind to when making outgoing connections    -p postfile     File containing data to POST. Remember also to set -T    -u putfile      File containing data to PUT. Remember also to set -T    -T content-type Content-type header to use for POST/PUT data, eg.                    'application/x-www-form-urlencoded'                    Default is 'text/plain'    -v verbosity    How much troubleshooting info to print    -w              Print out results in HTML tables    -i              Use HEAD instead of GET    -x attributes   String to insert as table attributes    -y attributes   String to insert as tr attributes    -z attributes   String to insert as td or th attributes    -C attribute    Add cookie, eg. 'Apache=1234'. (repeatable)    -H attribute    Add Arbitrary header line, eg. 'Accept-Encoding: gzip'                    Inserted after all normal header lines. (repeatable)    -A attribute    Add Basic WWW Authentication, the attributes                    are a colon separated username and password.    -P attribute    Add Basic Proxy Authentication, the attributes                    are a colon separated username and password.    -X proxy:port   Proxyserver and port number to use    -V              Print version number and exit    -k              Use HTTP KeepAlive feature    -d              Do not show percentiles served table.    -S              Do not show confidence estimators and warnings.    -q              Do not show progress when doing more than 150 requests    -l              Accept variable document length (use this for dynamic pages)    -g filename     Output collected data to gnuplot format file.    -e filename     Output CSV file with percentages served    -r              Don't exit on socket receive errors.    -m method       Method name    -h              Display usage information (this message)