2.5 KiB
+++ noatcards = True isdraft = False +++
Application layer
Application layer - Introduction
_Source: Intro to architecting systems for scale _
Separating out the web layer from the application layer (also known as platform layer) allows you to scale and configure both layers independently. Adding a new API results in adding application servers without necessarily adding additional web servers.
The single responsibility principle advocates for small and autonomous services that work together. Small teams with small services can plan more aggressively for rapid growth.
Workers in the application layer also help enable asynchronism .
Microservices
Related to this discussion are microservices , which can be described as a suite of independently deployable, small, modular services. Each service runs a unique process and communicates through a well-definied, lightweight mechanism to serve a business goal. 1
Pinterest, for example, could have the following microservices: user profile, follower, feed, search, photo upload, etc.
Service Discovery
Systems such as Zookeeper can help services find each other by keeping track of registered names, addresses, ports, etc.
Disadvantage(s) : application layer
- Adding an application layer with loosely coupled services requires a different approach from an architectural, operations, and process viewpoint (vs a monolithic system) .
- Microservices can add complexity in terms of deployments and operations.