Nginx Plus monitoring - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is Nginx Plus monitoring?

Nginx Plus monitoring is the process of tracking the performance and health of Nginx Plus servers using built-in tools and APIs to ensure smooth operation.

beginner

Which API does Nginx Plus provide for monitoring?

Nginx Plus provides a built-in RESTful API called the Nginx Plus API that exposes metrics about server status, upstreams, connections, and more.

intermediate

How can you enable the Nginx Plus status API in the configuration?

You enable it by adding the 'api' directive inside a location block, for example:

location /api {
  api;
}

beginner

Name two key metrics you can monitor with Nginx Plus API.

You can monitor active connections and upstream server health status among other metrics.

intermediate

What is the benefit of using Nginx Plus monitoring over open-source Nginx?

Nginx Plus monitoring offers real-time detailed metrics and health checks built-in, which are not available in open-source Nginx without extra tools.

What URL path is commonly used to access the Nginx Plus API status?

A /metrics

B /api

C /status

D /health

The Nginx Plus API is typically exposed under the /api location in the server configuration.

Which of the following is NOT a metric provided by Nginx Plus API?

A CPU temperature

B Active connections

C Upstream server health

D Request rates

Nginx Plus API does not provide hardware metrics like CPU temperature.

How do you enable the Nginx Plus API in the configuration?

A Add 'api;' inside a location block

B Add 'status on;' in http block

C Install a third-party module

D Enable 'monitoring on;' directive

The 'api;' directive inside a location block enables the Nginx Plus API.

What type of API is the Nginx Plus monitoring API?

A SOAP API

B GraphQL API

C RESTful API

D gRPC API

Nginx Plus monitoring API is a RESTful API providing JSON data.

Which benefit does Nginx Plus monitoring provide over open-source Nginx?

A Supports only static sites

B Free to use

C No configuration needed

D Built-in real-time metrics

Nginx Plus includes built-in real-time metrics and health checks not available in open-source Nginx.

Explain how to enable and access Nginx Plus monitoring API.

Think about the configuration inside the server block and how you get data from the browser or tools.

List key metrics you can monitor with Nginx Plus and why they are useful.

Consider what helps you know if your server is working well.

Practice

1. What is the main purpose of the Nginx Plus monitoring API endpoint?

easy

A. To provide live data about server traffic and health

B. To serve static website files

C. To configure SSL certificates automatically

D. To block unwanted IP addresses

Solution

1. Step 1: Understand Nginx Plus monitoring role

   Nginx Plus monitoring API endpoint is designed to show live server data such as traffic, errors, and health.

2. Step 2: Identify the correct purpose

   Serving static files, configuring SSL, or blocking IPs are unrelated to monitoring API.

3. Final Answer:

   To provide live data about server traffic and health -> Option A

4. Quick Check:

   Monitoring API = live server data [OK]

Hint: Monitoring API shows live server info, not config or files [OK]

Common Mistakes:

• Confusing monitoring API with static file serving
• Thinking it manages SSL certificates
• Assuming it blocks IP addresses

2. Which configuration snippet correctly enables Nginx Plus monitoring API at the path /api?

easy

A. location /api { api; }

B. location /api { proxy_pass http://backend; }

C. location /api { return 404; }

D. location /api { root /var/www/html; }

Solution

1. Step 1: Recall correct syntax for enabling Nginx Plus API

   The directive api; inside a location block enables the monitoring API endpoint.

2. Step 2: Compare options

   Only location /api { api; } uses api; directive. Others proxy, return 404, or serve files, which do not enable monitoring API.

3. Final Answer:

   location /api { api; } -> Option A

4. Quick Check:

   Enable API = location with api; directive [OK]

Hint: Use 'location /api { api; }' to enable monitoring [OK]

Common Mistakes:

• Using proxy_pass instead of api directive
• Returning 404 disables the endpoint
• Serving files does not enable API

3. Given this Nginx Plus config snippet, what will be the output when accessing /api?

location /api {
    api;
}

medium

A. A 404 Not Found error

B. A JSON response with live server metrics

C. The contents of /api directory on disk

D. A redirect to another URL

Solution

1. Step 1: Understand the api; directive effect

   The api; directive enables the Nginx Plus monitoring API, which returns live server data in JSON format.

2. Step 2: Analyze the response type

   Accessing /api returns JSON with metrics, not a 404, file contents, or redirect.

3. Final Answer:

   A JSON response with live server metrics -> Option B

4. Quick Check:

   api; returns JSON metrics [OK]

Hint: api; returns JSON live metrics at /api [OK]

Common Mistakes:

• Expecting file contents instead of JSON
• Thinking it returns 404 error
• Assuming it redirects

4. You added this config to enable Nginx Plus monitoring but get a 404 error when accessing /api:

location /api {
    api
}

What is the likely cause?

medium

A. The api directive requires a parameter

B. Wrong location path, should be /monitor

C. Nginx Plus monitoring is not supported on this server

D. Missing semicolon after api directive

Solution

1. Step 1: Check syntax of the api directive

   The api directive must end with a semicolon (api;). Missing it causes config errors and 404 responses.

2. Step 2: Evaluate other options

   The location path /api is correct, monitoring is supported, and api directive takes no parameters.

3. Final Answer:

   Missing semicolon after api directive -> Option D

4. Quick Check:

   Directive missing semicolon = 404 error [OK]

Hint: Always end directives with semicolon ; [OK]

Common Mistakes:

• Omitting semicolon after api directive
• Changing location path unnecessarily
• Assuming api directive needs parameters

5. You want to monitor multiple Nginx Plus servers centrally. Which approach using the monitoring API is best?

hard

A. Use location /api { proxy_pass http://backend; } to forward monitoring requests

B. Set up a single Nginx Plus server with location /api { api; } and proxy all traffic through it

C. Configure each server with location /api { api; } and use a script to fetch JSON from each server's /api endpoint

D. Disable the monitoring API and use log files only

Solution

1. Step 1: Understand monitoring API usage per server

   Each Nginx Plus server exposes its own live data at /api when configured with api;.

2. Step 2: Centralize monitoring by fetching data

   A script or tool can query each server's /api endpoint to collect and aggregate metrics centrally.

3. Step 3: Evaluate other options

   Proxying all traffic through one server or disabling API loses direct live data. Proxy_pass does not enable monitoring API.

4. Final Answer:

   Configure each server with location /api { api; } and use a script to fetch JSON from each server's /api endpoint -> Option C

5. Quick Check:

   Each server exposes API; central script collects data [OK]

Hint: Enable api; on each server, fetch data centrally via script [OK]

Common Mistakes:

• Trying to proxy monitoring API through one server
• Disabling API and relying only on logs
• Misusing proxy_pass for monitoring API