Apache bench, (ab) is a benchmarking program that ships with the Apache web server. While it may not be the most sophisticated tool, it is still very useful.

Apache bench should be run from a remote client since running it on the web server will skew the results down. Ideally, it should be run from multiple remote clients at the same time from different networks to better simulate actual web traffic.

To measure HTTP GET performance, use:

ab -n 10000 -c 25 URL

The -n is the number of requests to make and -c is the number of concurrent requests to make.

To measure HTTP PUT performance (form submissions), use:

ab -n 10000 -c 25 -p postfile.txt URL

The test PUT file, postfile.txt, does not have a to be a formatted as a valid PUT request, it can be a plain text file of the length you want to test.

Here is a sample report:

This is ApacheBench, Version 1.3d <$Revision: 1.73 $> apache-1.3
Copyright (c) 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Copyright (c) 1998-2002 The Apache Software Foundation, http://www.apache.org/

Benchmarking linuxboxadmin.com (be patient).....done
Server Software:
Server Hostname: linuxboxadmin.com
Server Port: 80

Document Path: /
Document Length: 15738 bytes

Concurrency Level: 4
Time taken for tests: 14.986 seconds
Complete requests: 100
Failed requests: 0
Broken pipe errors: 0
Total transferred: 1599796 bytes
HTML transferred: 1576465 bytes
Requests per second: 6.67 [#/sec] (mean)
Time per request: 599.44 [ms] (mean)
Time per request: 149.86 [ms] (mean, all requests)
Transfer rate: 106.75 [Kbytes/sec] received

Connnection Times (ms)
              min  mean[+/-sd] median   max
Connect:       79    93    9.7     93   122
Processing:   403   503   32.1    509   564
Waiting:      322   503   32.1    509   564
Total:        403   597   28.5    599   654

Percentage of the requests served within a certain time (ms)
50% 599
66% 605
75% 613
80% 619
90% 628
95% 638
98% 648
99% 654
100% 654 (last request)