The following status information is provided:
Active connections - the current number of active client connections including Waiting connections.
Accepts - the total number of accepted client connections.
Handled - the total number of handled connections. Generally, the parameter value is the same as accepts unless some resource limits have been reached (for example, the worker_connections limit).
Requests - the total number of client requests.
Reading - the current number of connections where nginx is reading the request header.
Writing - the current number of connections where nginx is writing the response back to the client.
Waiting - the current number of idle client connections waiting for a request.
https://nginx.org/en/docs/http/ngx_http_stub_status_module.html