We have reviewed different concepts for concurrency and concurrent programming for components of a scalable web architecture in the previous three chapters. We will summarize our results by providing recommendations for each stage. As we have reviewed the components with varying details, also the scope of the advices differ. Understanding the implications of different server architectures helps to provide insights on the expected performance.
The application logic represents the core of a web application. It is usually the part of the architecture that contains the specific code implemented by own developers. Application code is often based on web frameworks or application containers. We limit our guidelines to concurrency concepts for this component. For distributed database systems, the impacts of different consistency guarantees and data models are in our main focus.