APIs. They are your trusted advisors. But can you always rely on them? API failures are a fact of life. Even if they don’t fail they can still perform poorly. Your application could be left hanging or worse, it might crash. What are the most common failures? And what can you do to avoid them?
Let’s first consider what an API is. It allows a programmer communicate with an application or service and ask that application to perform a task. Although you may not be able to see what the API does with your data or your request, if it works properly, all that is required is to learn how to use the API. However, this is not enough to ensure APIs work properly.
This article will discuss three reasons an API may fail or underperform and how DevOps engineers can fix them.
What are the causes of an API failure?
API failures can occur for many reasons. However, most of them can be reduced to these three main culprits:
- Software updates are too rapid.
- Communication breakdowns between teams.
- Incompatible data with your API.
Let’s get into each one of these topics more deeply.
Sometimes software changes can take some time to appear in the documentation. An API call that worked in the previous version of another program might not work in the current version. It might now need different syntax, new arguments or new formatting for existing argument, or may produce data in an unexpected format.
Backward compatibility — Or Not?
API developers should strive to maintain backward compatibility so that API calls from the past work. They will also have updated API documentation to reflect these changes. Backward compatibility is not always possible or available for a limited time. Non-updated API calls won’t work after the grace period.
New changes are not likely to cause problems if you add an API to your code using the most recent documentation. You’ll be taking into consideration the new changes when you integrate the API into your app. If the API calls are in your code for a while, it is possible to not notice the changes until they fail. You may not realize the API is failing until it happens.
Go to the Source
It is possible that the documentation you use may not be current. It is possible to get the documentation directly from the developer site. However, it may not be perfect. It is easy to use outdated documentation with open-source software, especially if it was found in a local directory or on a site that appeared in a search engine.
If in doubt, or even if you aren’t, go straight to the source.
Dependencies Can Change
This applies to all dependencies, support applications, and services that may be used by the other API. Your developers might have not been tracking all changes to the other program. This could lead to your API call failing because an API call was not updated. This isn’t fair, but it happens. If it does, it may be time to do some detective work to find the root cause.
Let’s get down to communication. There is a good chance that the program or service you are trying to connect to is located somewhere online. This is in contrast to the possibility that it runs on the same computer or LAN as your app, which was probably the case decades ago. It could be an application that runs on a cloud-based server or a service integrated into a cloud platform infrastructure. From your code’s point of view, it may be a URL or an abstract proxy address.
Seamless redirection is not a given
What happens if the connection fails to work? If the hosting service is down, overloaded with requests or if there’s a problem in the communications infrastructure? Sometimes, your call will be redirected gracefully to another address. You may get a 3xx response code that requires you to take action, a 4xx, 5xx, or even no response.
Don’t Hang Up
Hanging applications are as dangerous as (and often more serious than) a crash. You need to plan for timeouts or failed connections if your application relies on an external service. Also, you must be able recognize and correct error codes and redirection. Your API call should be returned gracefully if your application is unable to continue to function. This will allow you to save user-entered data and prevent your application from being rerouted.
Your API call is likely one of many connections. It takes data from upstream and moves it downstream. Then, the response is passed on either back upstream or in another direction. It is possible that you don’t know where the data came from or what has happened to it. What happens if the API doesn’t require it? Or what does the other program expect? What happens if the text contains unacceptable characters? )?
Validate, check, and filter
If you’re lucky, you might get an error code from the other program. You may not get a response from the other program, or it may send bad data back to your application. This, among many other reasons, is why validation data is important. It checks for type and formatting issues, and filters out any that should not be there.
There are more API traps than you think
API failures can also be caused by slow connections or servers, security certificate or other issues, vendor limits (traffic volume and subscription expiration), DDoS attacks on large portions of infrastructure, or any other factors.
API failures are not what the users will see. They will see your program failing and hold you accountable. API failures should be anticipated and prepared for just like any other bug or failure.
To prevent API failures, API testing is a great way to avoid them. You can also monitor performance to keep track of it. aisle-won 360deg API Testing allows teams to quickly create API tests and track APIs throughout their development lifecycle. aisle-won allows data validation using flexible and powerful assertions.
While you may not be in a position to stop APIs failing, you can minimize the damage and keep your application from being shut down by an API failure.
Get aisle-won API testing & monitoring free of charge today.