Apache web server benchmark tool ab

ab is a tool for benchmarking your Apache HTTP server. It is designed to give an impression of how Apache installation performs. This especially shows how many requests per second certain Apache installation is capable to serve.

Manual of ab is rather extensive, so here is just useful example of it’s usage:

ab -n 100 ubuntu.com/

will send 100 requests to Apache server of Ubuntu’s web site. Here it’s output:

This is ApacheBench, Version 2.0.40-dev <$Revision: 1.146 $> apache-2.0
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Copyright 2006 The Apache Software Foundation, http://www.apache.org/

Benchmarking ubuntu.com (be patient).....done

Server Software: Apache/2.2.3
Server Hostname: ubuntu.com
Server Port: 80

Document Path: /
Document Length: 281 bytes

Concurrency Level: 1
Time taken for tests: 22.87165 seconds
Complete requests: 100
Failed requests: 0
Write errors: 0
Non-2xx responses: 100
Total transferred: 49000 bytes
HTML transferred: 28100 bytes
Requests per second: 4.53 [#/sec] (mean)
Time per request: 220.872 [ms] (mean)
Time per request: 220.872 [ms] (mean, across all concurrent requests)
Transfer rate: 2.13 [Kbytes/sec] received

Connection Times (ms)
min mean[+/-sd] median max
Connect: 88 100 5.5 100 133
Processing: 113 119 4.3 118 132
Waiting: 111 116 4.4 115 128
Total: 205 220 9.0 219 259

Percentage of the requests served within a certain time (ms)
50% 219
66% 222
75% 230
80% 231
90% 231
95% 234
98% 239
99% 259
100% 259 (longest request)

I found this utility very useful to check performance of newly installed and configured Apache (httpd).