Nginx status page can give realtime data about Nginx’s health. It can help you tweak few Nginx config. Status data can be used in load-balancer env also.
Requirement
Nginx must be compiled with HttpStubStatusModule module. You can check that by running following command:
nginx -V 2>&1 | grep -o with-http_stub_status_module
If you see following output, you are good to go ahead. Otherwise, refer this post to install nginx-full.
with-http_stub_status_module
Nginx Config
You need to add following to a nginx site, say example.com, inside server {..} block.
location /nginx_status {
stub_status on;
access_log off;
allow 1.1.1.1;
deny all;
}
Make sure you replace 1.1.1.1 with your machine’s IP-address. It’s good idea to keep this page accessible to only you.
Output:
Once you codes and reload nginx config, just visit: http://example.com/nginx_status You will see output like below:
Active connections: 43 server accepts handled requests 7368 7368 10993 Reading: 0 Writing: 5 Waiting: 38
Interpretation
- Active connections – Number of all open connections. This doesn’t mean number of users. A single user, for a single pageview can open many concurrent connections to your server.
- Server accepts handled requests – This shows three values.
- First is total accepted connections.
- Second is total handled connections. Usually first 2 values are same.
- Third value is number of and handles requests. This is usually greater than second value.
- Dividing third-value by second-one will give you number of requests per connection handled by Nginx. In above example, 10993/7368, 1.49 requests per connections.
- Reading – nginx reads request header
- Writing – nginx reads request body, processes request, or writes response to a client
- Waiting – keep-alive connections, actually it is
active – (reading + writing).This value depends on keepalive-timeout. Do not confuse non-zero waiting value for poor performance. It can be ignored. Although, you can force zero waiting by settingkeepalive_timeout 0;