investigating apache benchmark failed request
I am just start using AB just today. Read couple of AB tutorial on new and thought give it a try for load testing my site.
After using it couple of time I got huge number of failed request. Can you explain what is mean by a failed request? How can I investigate more for this issue?
Sample AB result:
-jailshell-3.2$ ab -n500 -c10 http://www.tweeting.tv/index.php
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 www.tweeting.tv (be patient)
Completed 100 requests
Completed 200 requests
Completed 300 requests
Completed 400 requests
Finished 500 requests
Server Software: Apache
Server Hostname: www.tweeting.tv
Server Port: 80
Document Path: /index.php
Document Length: 242861 bytes
Concurrency Level: 10
Time taken for tests: 97.846330 seconds
Complete requests: 500
Failed requests: 481
(Connect: 0, Length: 481, Exceptions: 0)
Write errors: 0
Non-2xx responses: 2
Total transferred: 121214449 bytes
HTML transferred: 121003283 bytes
Requests per second: 5.11 [#/sec] (mean)
Time per request: 1956.927 [ms] (mean)
Time per request: 195.693 [ms] (mean, across all concurrent requests)
Transfer rate: 1209.78 [Kbytes/sec] received
Connection Times (ms)
min mean[+/-sd] median max
Connect: 0 1503 1675.5 1 9036
Processing: 130 393 285.1 319 2382
Waiting: 92 244 226.3 192 2180
Total: 153 1896 1726.2 1121 10374
Percentage of the requests served within a certain time (ms)
50% 1121
66% 3308
75% 3355
80% 3375
90% 3451
95% 3603
98% 4163
99% 9315
100% 10374 (longest request)
N.B. I am using Hostgator Linux shared server.
Answer
This is an issue with dynamic pages, it happens because the Content-Length can vary between the requests. When using ab with such pages you need to use the -l option.
-l Accept variable document length (use this for dynamic pages)