2.7 Understand Technology LimitationsApril 15th, 2009 — Marieke Guy
API providers have technical limitations too and a good understanding of these will help keep your system running efficiently. Think about what will happen when the backend is down or slow and make sure that you cache remote sources aggressively. Try to build some pacing logic into your system. It’s easy to overload a server accidentally, especially during early testing. Ask the service provider if they have a version of the service that can be used during testing. Have plans for whenever an API is down for maintenance or fails. Build in timeouts, or offline updates to prevent a dead backend server breaking your application. Make sure you build in ways to detect problems. Providers are renowned for failing to provide any information as to why they are not working.
Write your application so it stores a local copy of the data so that when the feed fails its can carry on. Make this completely automatic so the system detects for itself whether the feed has failed. However, also provide a way for the staff to know that it has failed. I had one news feed exhibit not update the news for 6 months but no one noticed because there was no error state.
You will also need to be weary of your own technology limitations. Avoid overloading your application with too many API bells and whistles. Encourage and educate end users to think about end-to-end availability and response times. If necessary limit sets of results. Remember to check your own proxy, occasionally data URLs may be temporarily blocked because they come from separate sub-domains.
Other technology tips include remember to register additional API keys when moving servers.