How do I stress test a web form file upload?

Question

I need to test a web form that takes a file upload. The filesize in each upload will be about 10 MB. I want to test if the server can handle over 100 simultaneous uploads, and still remain responsive for the rest of the site.

Repeated form submissions from our office will be limited by our local DSL line. The server is offsite with higher bandwidth.

Answers based on experience would be great, but any suggestions are welcome.

Answer 1

Use the ab (ApacheBench) command-line tool that is bundled with Apache (I have just discovered this great little tool). Unlike cURL or wget, ApacheBench was designed for performing stress tests on web servers (any type of web server!). It generates plenty statistics too. The following command will send a HTTP POST request including the file test.jpg to http://localhost/ 100 times, with up to 4 concurrent requests.

ab -n 100 -c 4 -p test.jpg http://localhost/

It produces output like this:

Server Software:        
Server Hostname:        localhost
Server Port:            80

Document Path:          /
Document Length:        0 bytes

Concurrency Level:      4
Time taken for tests:   0.78125 seconds
Complete requests:      100
Failed requests:        0
Write errors:           0
Non-2xx responses:      100
Total transferred:      2600 bytes
HTML transferred:       0 bytes
Requests per second:    1280.00 [#/sec] (mean)
Time per request:       3.125 [ms] (mean)
Time per request:       0.781 [ms] (mean, across all concurrent requests)
Transfer rate:          25.60 [Kbytes/sec] received

Connection Times (ms)
          min  mean[+/-sd] median   max
Connect:        0    0   2.6      0      15
Processing:     0    2   5.5      0      15
Waiting:        0    1   4.8      0      15
Total:          0    2   6.0      0      15

Percentage of the requests served within a certain time (ms)
  50%      0
  66%      0
  75%      0
  80%      0
  90%     15
  95%     15
  98%     15
  99%     15
 100%     15 (longest request)