In this article, I will be talking about monoliths and microservice system architecture. Recently Hrishikesh Bhaskaran gave a talk on this topic at Facebook F8 meetup. Th.is talk inspired me and changed my thoughts about both. So I am going to highlight some of key takeways in this blogpost.
Monoliths
Monoliths can roughly be described as a big combined stack. it includes user interfaces and data access all in the same silo. So taking Social media as an example - all functionalities like userfeed, authentication, photos are all enclosed in a single application.
In case of Microservices, all the functionalities are seperated whenever required so we can use the bleeding edge technology whenever required.
Some basic terminology
Vertical scaling - increase RAM/My of CPU service Horizontal scaling - more replicas Loadbalancers - A load balancer is a device that distributes network or application traffic across a cluster of servers. Load balancing improves responsiveness and increases availability of applications. One of the easiest methods for scaling.
Why Monlith are easy to build?
- Less time for initial build
- Easy installation and deployment of services
- testing of service is very easy
Next we will discuss about microservices.Today microservices is a buzz word like AI, Machine Learning, Blockchain. This makes everyone very tempting to use microservices for whatever you make. As Hrishi said, please note monolith is not a out-dated technology as many think about it. It recommended to use monoliths when you are building a stack with no previous experience in it.
Micoservices
Some of the characteristics of microservices are:
- Per Martin Fowler and other experts, services in a microservice architecture (MSA) are often processes that communicate over a network to fulfill a goal using technology-agnostic protocols such as HTTP.
- Increased uptime for servers, as only one service need to made down to scale a paricular component compared to monoliths which has downtime for entire services.
- Using new technologies is easy
- Various Database and Language support for each services is possible like R, JS, Python. You run backend both in flask, rust and golang for various microservices. This allows in using the best of everything.
- Helps in easy onboarding for new member and help in agile architecture of development, which is popular now.
Disadvantages:
Microservices is distributed computing, so there is a lot of problems are associated with it: - All services should have same IP, the network use VPC for communication of various microservices to each other. - We are assuming usually lattency is zero, bandwidth is infinity in distributed computing. This may not always hold true in real world systems. - Using microservice for small 2 teams is not ideal usually. - Various services in microservice, can communicate each other. So seperate data cost is needed for internal communication.
When to use Monoliths vs Microservices
This is actually a million dollar question according to me. Personally I had always used microservices as my defacto method of development and encountered lot of issues with it. Once I was developing a website for 1 day use purpose, to be used at-most maximum of 100 people. And using microservices made it a pain to deploy the service and eventually one of my friends solved the issue by using a static website with everything hard coded and was deployed in less than 1 hour.
Moral of story: Use the right technology at the right time
Monolith is ideal for new projects which are meant to be served in a low/medium scale with less knowledge on how to build it.
Microservices are ideal for projects which you already have some domain experience on and know what exactly are the services split up needed for satisfying your requirement.
Thanks for reading the article :).