In my experience, the complicated setups that are justified by the argument of "reliability" have more downtime then a single VPS. The reason is probably that there are more moving parts and more has to be maintained / can go wrong.
These days, a single VPS in the right datacenter has excellent uptime.
I've also had very high reliability rates with a single VPS. They've actually given me less downtime than AWS services at times.
I can't hit four nines reliably with single VPS platforms on my typical workloads, I need load balancers and redundant app servers. I could quite likely hit three nines using single VPSes. But if a client wants 99.9% SLAs, they'll be paying for HA and I'll deploy redundant ec2 instances, multi region RDS, and an ELB. And charge them 3 or 4 times what the OP is spending for it. (And I'll almost always deliver 99.99% availability.)
For my stuff or friends or people I'm doing cost saving favours for, I'll explain how much extra it costs to guarantee less then an hour of downtime a month, the realistic expectations and historical experience of how much downtime an non-HA platform might have in their use case, and often choose along with them a single VPS (or even dirt cheap cpanel hosting) while understanding and accepting the risks associated with saving upwards of a couple of hundred bucks per month.
I know this, because I have gone through these issues with each of my projects. Just recently an infinite loop bug in a cron job ground my "single VPS" setup to a halt (and took the web server with it).
It still has a redundant slave because I'm not going to bet my reputation on everything going right.
To be fair I can't be sure because a less than 5 minutes downtime would probably go unnoticed, but the fact is I never hear about this server.
> In my experience, the complicated setups that are justified by the argument of "reliability" have more downtime then a single VPS. The reason is probably that there are more moving parts and more has to be maintained / can go wrong.
> These days, a single VPS in the right datacenter has excellent uptime.
Again, maybe in your experience but that's not universal. There's literally no redundancy with running everything off a single VPS and if that datacenter has network or hardware problems, then your service is down.
Is redundancy necessary for the scale of OP's app considering it provides 0 income? Most likely not, but that's a decision they've decided on and there's nothing wrong with that.
What does excellent uptime mean in your book? With Digital Ocean's AM2 region I had regular downtime every few weeks and while I'm alright with it, if I had another VPS in another datacenter it would've had next to no effect on the customer experience. But an hour or more of downtime every two weeks isn't excellent.
What does excellent uptime
mean in your book?
Over the last years, across multiple datacenters, I have seen maybe one or two short downtimes per year. None ever lasting more then 5 minutes.