Thanks. Indeed, I'm just using one PostgreSQL master, with no HA, but plan to set something up later, and have put repmgr on my todo list. (I'm the post author.)
Yes. It's currently using 80GB of disk, so regarding disk space I can scale for years. I have tiering system where older data gets stored in Google cloud storage, and grabbed on demand. So regarding space, there isn't an issue scaling up. It's also trivial to increase disk space on live VMs on GCE.
> So you scale the database by switching to a stronger machine?
That's my plan. We're at about 50% overall load as I write this, and here's the usage on the database server: "load average: 0.09, 0.16, 0.17". We're collecting historical Prometheus and other monitoring about load and queries, etc. By the time we need 32 cpus (the GCE limit), either the GCE limit will be raised, the company will be dead (no way in hell), or the company will be wildly successful. So in the only case in which I need to scale out, it will be an exciting new problem that I can hire a team to help with, and we'll benefit from understanding exactly what the problem is we need to solve.
I have wasted an enormous amount of time until now due to premature worry about scalability, fueled by my naive assumptions about how quickly SageMathCloud would grow.
