If you’ve ever written a web-app you’ve probably wondered how well it will hold up once the world discovers your awesome service. Will it work if you get dugg? What happens if 200 people all try to access your site at once? This is where benchmarking can provide some useful numbers to give you an idea as to how your server will hold up.
Apache Benchmark can be a helpful tool to determine response times based on various traffic patterns. It lets you determine how many requests per second your server should be able to handle, and how long each visitor will have to wait to receive a response.
The syntax is pretty straight forward:
ab -c 10 -n 1000 http://yourdomain.com/ |
(note the trailing / if you are wanting to test your main document). The -c tells ab to make 10 concurrent requests at a time and -n tells it to make 1000 requests total. This will create output similar to
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 yourdomain.com (be patient) Completed 100 requests Completed 200 requests Completed 300 requests Completed 400 requests Completed 500 requests Completed 600 requests Completed 700 requests Completed 800 requests Completed 900 requests Completed 1000 requests Finished 1000 requests Server Software: Apache/2.2.9 Server Hostname: yourdomain.com Server Port: 80 Document Path: / Document Length: 240 bytes Concurrency Level: 10 Time taken for tests: 20.824 seconds Complete requests: 1000 Failed requests: 0 Write errors: 0 Non-2xx responses: 1000 Total transferred: 565000 bytes HTML transferred: 240000 bytes Requests per second: 48.02 [#/sec] (mean) Time per request: 208.238 [ms] (mean) Time per request: 20.824 [ms] (mean, across all concurrent requests) Transfer rate: 26.50 [Kbytes/sec] received Connection Times (ms) min mean[+/-sd] median max Connect: 59 120 376.0 68 3093 Processing: 61 80 44.0 70 466 Waiting: 61 80 44.0 70 466 Total: 121 200 377.8 144 3165 Percentage of the requests served within a certain time (ms) 50% 144 66% 151 75% 156 80% 162 90% 176 95% 203 98% 520 99% 3132 100% 3165 (longest request) |
From this we can see that the server tested was able to hand approximately 48 requests per second and was able to process 1000 requests in just under 21 seconds. Whether or not these are acceptable values completely depends on the requirements of your project and application.
You are also able to send in post and cookie data (check the man pages for instructions on how to do that) if you would like to benchmark an authentication process or some form processing.
I’ve found ab to be a useful tool to determine which pages on a site are taking too long to server / bogging down the server. It’s certainly not the end-all / be-all but can get you pointed in the right direction. After collecting some baseline data though ab, it may give you some ideas as to what code to optimize or where to implement caching on your server.
Remember, be kind and only stress test your own servers. Other people may not take kindly to you hammering their server just to see how they hold up.
edit
Just a quick note about dynamic urls. You can use these if you put single quotes around the entire url. For example:
ab -c 5 -n 2000 ‘http://yourdomain.com/index.php?id=27&action=edit’
Tags: server admin, system admin, web development