2909 views • Designing μ-services
Should every microservice have its own database?
Microservices need some persistence to store the state of the application. They also need to be loosely coupled with others so as to be autonomous and having a separate database for itself really helps, and this is the Database Per Service pattern.
The importance of having a database per service can be seen when we model a social network. For every usecase, we would need a specialized database to keep our latencies to a bare minimum.
Because the databases are separate, the services could not connect to other databases and would have to directly talk to each other making them loosely coupled.
Services can pick the best database for their usecase making them super performant and efficient. For example, picking a Graph database to model relations in social networks instead of relational.
Services can choose their scaling strategies as per the load it is getting; be it vertical, horizontal, replicas, partitioned, or decentralized.
When any database is experiencing an outage only the services that are directly or indirectly dependent on it get affected and everything else continues to operate normally. For example, we can continue to accept the payments even when the profile service is down.
Compliance requires us to make changes in how our data is stored and moved across. Separate databases would help us in implementing changes on a fraction of data instead of the whole.
If we need strong consistency across, we would need distributed transactions and those are expensive and complex to implement.
Conveying updates from one service to another would require us to have message brokers, thus adding more things to manage and maintain.
Having a database per service bloats up our infra and we would need to build expertise in maintaining and managing them.
If you like what you read subscribe you can always subscribe to my newsletter and get the post delivered straight to your inbox. I write essays on various engineering topics and share it through my weekly newsletter.
2635 views • 131 likes • 2022-07-04
As your application evolves, supporting multiple types of clients like Desktop, Mobile apps, etc becomes tricky. The bac...
938 views • 52 likes • 2022-06-27
Running microservices in isolation does not make any sense. To get something done, multiple microservices need to talk t...
938 views • 41 likes • 2022-06-20
An engineer working on Microservices should not only just focus on engineering; there are so many other aspects to look ...
701 views • 29 likes • 2022-06-17
We all love creating microservices, but what if every team creates its own microservice uniquely and uses its own conven...
A set of courses designed to make you a better engineer and excel at your career; no-fluff, pure engineering.
Being a passionate engineer, I love to talk about a wide range of topics, but these are my personal favourites.
Arpit's Newsletter read by 17000+ engineers
🔥 Thrice a week, in your inbox, an essay about system design, distributed systems, microservices, programming languages internals, or a deep dive on some super-clever algorithm, or just a few tips on building highly scalable distributed systems.
Powered by this tech stack.