Comment by franga2000
13 hours ago
And I don't understand the obsession with server-based databases for single apps. Especially in containerised setups, every "app" gets its own database anyways, and if the app is further broken down into services, they usually communicate between each other and not with a shared database. So in those cases, what do you gain by pulling the database out of the "process" and onto the other end of a socket? In most cases, absolutely nothing. So why bother?
Don't get me wrong, I've worked with plenty of server-based databases, including proper dedicated database servers. It's great tech and often the best tool for the job. But not always and I'd argue not in the majority of uses.
“Especially in containerised setups, every "app" gets its own database anyways, and if the app is further broken down into services, they usually communicate between each other and not with a shared database. “
You seem to be talking about a vastly different use case.
Containerized apps having their own database? What? Aren’t these types of containers stateless? I always very much try to keep state out of app containers.
What kind of data storage are we talking about?
If an app needs a database, it gets a database server container, instead of getting a user and database on a shared database server as things used to be done. Every little django app has its own postgres container. Every wordpress site gets its own mysql container. That is the modern way.
Those database containers get a PVC/volume/mount for their data dirs. The only thing ever connecting to them is their "owner" application container. So at that point, why not drop the postgres container and PVC mount a sqlite directory in the app container? The result is the same.
And when you need to scale to thousands of instances of your microservice?
3 replies →
Yes if you run a database server like an embedded application database, then it won’t be very different from an embedded application database.
Every container gets its own database?
Yes? Well, every "app", as I quite explicity wrote. Look up the docker compose file or helm chart for basically any app. I'm running dozens of apps, each with their own postgres, redis and nginx containers alongside the main application server. That's what the stack is designed for.
The Compose file is written like that so you can quickly try the app without setting up extra dependencies. Usually not for production use.
Especially since in production you might want to scale the parts separately. I like to have a Postgres cluster to connect where backup is already handled, and the app then doesn’t have any persistent data, doesn’t need any network volume mounts.