Book Image

Building Python Microservices with FastAPI

By : Sherwin John C. Tragura
3 (2)
Book Image

Building Python Microservices with FastAPI

3 (2)
By: Sherwin John C. Tragura

Overview of this book

FastAPI is an Asynchronous Server Gateway Interface (ASGI)-based framework that can help build modern, manageable, and fast microservices. Because of its asynchronous core platform, this ASGI-based framework provides the best option when it comes to performance, reliability, and scalability over the WSGI-based Django and Flask. When working with Python, Flask, and Django microservices, you’ll be able to put your knowledge to work with this practical guide to building seamlessly manageable and fast microservices. You’ll begin by understanding the background of FastAPI and learning how to install, configure, and use FastAPI to decompose business units. You’ll explore a unique and asynchronous REST API framework that can provide a better option when it comes to building microservices. After that, this book will guide you on how to apply and translate microservices design patterns in building various microservices applications and RESTful APIs using the FastAPI framework. By the end of this microservices book, you’ll be able to understand, build, deploy, test, and experiment with microservices and their components using the FastAPI framework.
Table of Contents (17 chapters)
1
Part 1: Application-Related Architectural Concepts for FastAPI microservice development
6
Part 2: Data-Centric and Communication-Focused Microservices Concerns and Issues
11
Part 3: Infrastructure-Related Issues, Numerical and Symbolic Computations, and Testing Microservices

Applying the CQRS design pattern

CQRS is a microservice design pattern responsible for segregating query transactions (reads) from the insert, update, and delete operations (writes). The separation of these two groups lessens the cohesion access to these transactions, which provides less traffic and faster performance, especially when the application becomes complex. Moreover, this design pattern creates a loose-coupling feature between the API services and the repository layer, which gives us an advantage if there are several turnovers and changes in the repository layers.

Defining the handler interfaces

To pursue CQRS, we need to create the two interfaces that define the query and the command transactions. The following code shows the interfaces that will identify the read and write transactions for Profile_Trainers:

class IQueryHandler: 
    pass 
class ICommandHandler: 
    pass

Here, IQueryHandler and ICommandHandler are informal...