Guide: Uptime Monitoring

Uptime Monitors check your public-facing services from our infrastructure at regular intervals to ensure they are available and responding correctly. If a check fails, 9n9s can notify you immediately.

Common Use Cases

• Websites & Landing Pages: Ensure your marketing site is online and accessible to users.
• API Endpoints: Monitor the health of your critical REST or GraphQL API endpoints.
• Public Services: Check if a specific TCP port on a server is open and responsive (e.g., a database or SSH port that is publicly accessible).

Creating an Uptime Monitor

1. From your project dashboard, click “Create Monitor”.
2. Select “Uptime” as the monitor type.
3. Fill out the configuration:
   • Name: A descriptive name, e.g., “Main Website” or “API Health Check”.
   • Protocol & Target: Choose from HTTP(S) or TCP Port.
     • For HTTP(S), enter the full URL to check (e.g., https://my-api.com/health).
     • For TCP Port, enter the host:port (e.g., my-db.example.com:5432).
   • Check Frequency: How often 9n9s should check your service (e.g., every 1 minute, 5 minutes). This may be limited by your account tier.
   • Request Configuration (for HTTP): You can customize the HTTP Method, add Custom Headers, and include a Request Body for POST or PUT requests.

Defining Success with Assertions

An “up” service is more than just a 200 OK response. Assertions let you define what a successful check looks like. You can add multiple assertions.

1. Status Code Assertion

The most common assertion. You can specify a single code or a range.

• Expected Status Code: 200 (for success)
• Expected Status Code: 2xx (for any success code from 200-299)
• Expected Status Code: 401 (to ensure an endpoint is correctly protected)

2. Response Body Assertion

Check the content of the response body. This is useful to ensure your service is returning the correct data, not just a generic success page.

• Operator: Contains or Does Not Contain
• Value: A string or a regular expression to match against.
• Example: For a health check endpoint that returns {"status": "ok"}, you could assert that the body Contains the string "ok".

3. Response Time Assertion

Ensure your service is performant. 9n9s will fail the check if the response time exceeds this threshold.

• Max Response Time: e.g., 500ms or 2s.

4. SSL/TLS Certificate Assertion (for HTTPS)

For HTTPS targets, 9n9s automatically checks the validity of your SSL/TLS certificate. You can configure an assertion to be warned a number of days before it expires.

• Expires in more than: 14 days.

If any of these assertions fail, the check is considered “Down”, and 9n9s will trigger your configured alerts.