Search code examples
javaspring-bootmicroservices

Is this microserviced?

I have created a simple blogging application using Spring Boot and RESTful APIs. I have connected the same to a MySQL database to run some SQL queries like those for adding a blog, deleting a blog, etc.

My questions are as follows:

  1. Does it mean that I have used a microservice architecture? When does an architecture become a microservice? (I ask because many similar websites call an application as microservice-based. Other than the main application, e.g., currency exchange instead of blogging, I see no other difference; for e.g., this one - it does have many more aspects, but they are not contributing to its microservice-ness, IMHO).

  2. Can I call an application as horizontally scalable if I am using microservice-based architecture?

Note: The tutorial I followed is here and the GitHub repo is here.

Solution

  • First of all: those aren't exact yes/no questions. I'll give you my opinion, but others will disagree.

    You have created what most people would agree qualifies as a Microservice. But a Microservice does not make a Microservice architecture, in the same way that a tree doesn't make a forest.

    A Microservice architecture is defined by creating a greater application that consists of several distributed components. What you have done is created a monolith (which is absolutely fine in most cases).

    Almost every talk about Microservices that I have attended has featured this advice: start with a monolith, evolve to microservices once you need it.

    Regarding the last question: your application is horizontally scalable if it is stateless. If you keep any session state, it can still be horizontally scalable, but you'll need a smart LB managing sticky sessions or distributed sessions. That's when things get interesting, and when you can start thinking about a Microservice architecture.

    Common problems are: how can I still show my customers my website, if the order database, cart service, payment provider etc. are down. Service discovery, autoscaling, retry strategies, evolving Rest apis, those are common problems in a Microservice architecture. The more of them you use and need, the more you can claim to have a Microservice architecture.