This is a list of commonly asked questions and the answers, with some extended explnation.
What's drogon's threading model and best prectices?
Drogon runs on a thread pool where the HTTP server threads as well as DB threads are created when
app().run() is called. It is a sequential task based system. Thus it is recommended to always use the asynchronous APIs or coroutines when possible. See Understanding drogon's threading model for detail.