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Continuous Monitoring for API Reliability

Anyone building APIs should know how well they perform. Without a view into your API reliability, you’ll be gambling that everything works as expected. API consumers—internal collaborators, partners, or other external developers—will discover if your API breaks and let you know about it. Continuous Monitoring can help you uncover these issues proactively.

Developers that use your API may also want to know how well it performs. You can only share this data if you’ve been collecting it. Let’s look at what makes an API reliable and how you can track it over time.

What Makes an API Reliable?

In addition to meeting business needs, the next goal of your API should be reliability. If your API only works sometimes, nobody will want to use it. API consumers want to build atop a service they can trust.

A reliable API should have:

  • Consistency: are your API endpoints predictable and well-documented?
  • Availability: how often do your API endpoints experience downtime?
  • Low Latency: how quickly (or slowly) does your API respond to requests?
  • Security: who can access your API, and do they comply with your terms and conditions?
  • Status: do you report outages and scheduled maintenance to your users?

A single API call can tell much of this story, but only for a snapshot of that moment. You can automatically make calls through API Monitoring, which will give you reliability metrics over time.

What is API Monitoring?

To understand how well your API performs, you need to track your key reliability metrics. You may be able to analyze API logs or create specific test calls to generate monitoring logs. API logs give detailed information about each time an API endpoint was requested, including who requested it, how long it took to execute, and if the request succeeded. 

Alerts are another important part of API monitoring because you need to know your API has failed as soon as possible. When you implement alerts, you can monitor with minimal human supervision. Without API monitors and alerts, your API will fail silently and you won’t know that it needs fixing.

Remember that your API consumers likely pass along a key or token as part of your API Authentication. One common monitoring mistake is only to check non-authenticated requests. You want your security to be part of your API monitoring plan, so include calls that closely resemble real requests, including authentication. You might separately consider which consumers are making the largest use of your API. Increased usage could be a sign of a potential security issue to investigate.

Logs and alerts allow your API to tell you what is broken and can even uncover signs of a future issue. To get the full benefits of API monitoring, you’ll want these checks happening regularly.

How to Continuously Monitor an API

While you can run a monitor once or periodically, the real value comes from seeing patterns and spotting anomalies. It’s important to understand your API performance over time. With continuous API monitoring you can:

  • Analyze long-term trends: How quickly is the number of requests growing?
  • Compare API performance over time: Are your responses slower than last week?
  • Debug your API: Your error rate just went up; what else changed around the same time?

Testing is a powerful tool to include in your monitoring arsenal. You should write tests for authentication, availability, and speed. Run tests regularly because a variety of factors can affect your API performance, and frequent testing will make it easy to identify when API degradation began.

You can combine alerts, tests, and the data they produce into a status page to report API performance to your API consumers. A status page should indicate which endpoints are available and a timeline of previous outages or issues, which can build trust.

You can’t get started too early. There’s a place for API monitoring and testing at every stage of the API lifecycle. By using this approach to continuously monitor your API, you will give your teams the data needed to make it more reliable.