Just to share another script that I hacked together to monitor my sites. Nginx is a great web server software and since I last wrote about it more than 2 years ago, I have since pretty much converted all my sites to Nginx (sorry Lighttpd).

Nginx came with this HTTP stub status module that you can get the current server status in a HTML page. However it’s not pretty comparing to Lighttpd’s and Apache’s. Moreover, the information it provides is a bit cryptic.

For example, when you browse to the stub status page (please refer to the wiki document linked earlier on how to set it up), all you get is 4 lines of text:

$ curl http://myserver/nginx_status
Active connections: 183
server accepts handled requests
 914384 914384 2725561
Reading: 3 Writing: 2 Waiting: 178

Not very meaningful. Instead, I wrote a small Python script (download here: nginxstats.py (2.3kb)) that does something like this:

$ ./nginxstats.py http://myserver/nginx_status
Conn     Conn/s     Request/s  Read  Write Wait
-------- ---------- ---------- ----- ----- -----
     157       9.57      31.07     0     2   155
     140      10.20      36.13     0     1   139
     147       9.33      33.60     0     4   143
     189      12.60      40.07     1     4   184
     164      13.07      41.53     5     2   157

Basically it fetches the data from the stub status page every 30 seconds (configurable in the script) and then do some calculation to find out how many connections have been established within the time frame, and what’s the average connections/second and requests/second. Similar to tools like vmstat, it basically runs continuously (until interrupted).

Very useful when you are getting slashdotted :)