I know that Lemmy is open source and it can only get better from here on out, but I do wonder if any experts can weigh in whether the foundation is well written? Or are we building on top of 4 years worth of tech debt?
I find that often the overhead from microservices is worse than any savings from dropping a megabyte worth of unused machine instructions from a binary.
When your microservices need to talk to each other (and I’m not sure how many services you could split out of Lemmy without them needing to talk to each other), you’re doing a bunch of HTTP requests that are way slower than just calling another function in your monolith.
I see this at work every day. We run a distributed monolith because someone thought microservices would be a good idea, but we can’t actually separate everything, so it’s usual for an incoming API call to make 2-3 more calls internally. It can get so, so slow.
Overly chatty micoservices are definitely an issue.
Changing your mindset to a microservice oriented architecture is not an easy feat, it’s something that took a lot of time for me to fully grasp (back in my architect/developer) days. Yes, you gain overhead that will need to be compensated for. But when do the benefits outweigh the disadvantages?
Here are some questions to ask during design: How much of this chattiness is because you are tightly coupling these services? Hom much should a microservice be talking between each other? Can you implement an event bus to handle that chatter between services?
Designing an application using microserves but just replicating the monolith application will give you scalability, but will not give resilience. What can you do to overcome that single point of failure? First, no more synchronous calls to these APIs, toss an event over then fence and move on. Degrade your application if the failure is something you can’t overcome, but don’t just stop the application because one API is no longer responsive.
Do you need everything to be a microservice? Probably not. The first thing you look at when moving from a monolith to microservice architecture is what makes the most sense to be moved. How much work can be offloaded to background jobs (using something like sidekiq)?
How do you handle installs? How many packages do we now have to create for this application to work?
There are a lot of questions that have to be answered before moving toward a microservice architecture. On top of that, there is a complete mindset change as to how the application works that needs to be accomplished. If you design your microservice application with a monolith application mindset, you’ll never realize any of the gains by making the move
I’m not into this topic, but i do want to share a talk by Joe Armstrong (creator of erlang).
https://www.youtube.com/watch?v=cNICGEwmXLU
The whole chanel is full of stuff like this.
