Check nginx-status

Overview

This check provides global nginx basic status information from the stub_status module.

For this check to work, enable the stub_status module:

# /etc/nginx/nginx.conf
server {
    location /server-status {
        stub_status;
        allow 127.0.0.1;    # only allow requests from localhost
        deny all;           # deny all other hosts
    }
}

Due to the fact that the stub_status <https://github.com/nginx/nginx/blob/master/src/http/modules/ngx_http_stub_status_module.c> module increments each counter at the exact moment a new request „object“ is created, even before any request header (including the URI) is parsed, there is unfortunately no way to tell Nginx not to count requests for a given URI. In other words: It is not possible to get stats only for a specific server block.

Fact Sheet

Check Plugin Download	https://github.com/Linuxfabrik/monitoring-plugins/tree/main/check-plugins/nginx-status
Check Interval Recommendation	Once a minute
Can be called without parameters	Yes
Compiled for	Linux, Windows
Requirements	Enable `stub_status`
Perfdata compatible to Prometheus	Yes

Help

usage: nginx-status [-h] [-V] [--always-ok] [-c CRIT] [--insecure]
                    [--no-proxy] [--timeout TIMEOUT] [-u URL] [-w WARN]
                    [--test TEST]

This check provides NGINX basic status information.

options:
  -h, --help            show this help message and exit
  -V, --version         show program's version number and exit
  --always-ok           Always returns OK.
  -c CRIT, --critical CRIT
                        Set the CRIT threshold for the number of active
                        connections. Default: >= 486
  --insecure            This option explicitly allows to perform "insecure"
                        SSL connections. Default: False
  --no-proxy            Do not use a proxy. Default: False
  --timeout TIMEOUT     Network timeout in seconds. Default: 8 (seconds)
  -u URL, --url URL     NGINX Server Status URL. Default:
                        http://localhost/server-status
  -w WARN, --warning WARN
                        Set the WARN threshold for the number of active
                        connections. Default: >= 460
  --test TEST           For unit tests. Needs "path-to-stdout-file,path-to-
                        stderr-file,expected-retc".

Usage Examples

./nginx-status --url http://nginx/server-status --warning 460 --critical 486

Output:

1 active concurrent conn; 3 accepted conns, 3 handled conns, 3 reqs; 1.0 req per conn; currently 0 receiving reqs, 1 sending response, 0 keep-alive conns

States

WARN if the number of total handled connections is not equal to the number of total handled requests.
WARN or CRIT if the active connections are above the specified thresholds.

Perfdata / Metrics

Name	Type	Description
nginx_connections_accepted	Continous Counter	The total number of accepted client connections.
nginx_connections_active	None	The current number of active client connections including `Waiting` connections. One user can have several concurrent connections to a server.
nginx_connections_handled	Continous Counter	The total number of handled connections. Generally both values are the same unless some resource limits have been reached (for example, the `worker_connections` limit).
nginx_connections_reading	None	The current number of connections where nginx is reading the request header.
nginx_connections_waiting	None	The current number of idle client connections waiting for a request. This number depends on the `keepalive_timeout`.
nginx_connections_writing	None	The current number of connections where nginx is writing the response back to the client.
nginx_http_requests_total	Continous Counter	The total number of client requests.
nginx_requests_per_connection	None	The number of handled requests per connection.

Credits, License

Authors: Linuxfabrik GmbH, Zurich
License: The Unlicense, see LICENSE file.