It’s more than just a managed service. RDS is Amazon’s managed database cloud service, but you still provision and pay for a specific virtual server with a certain number of CPUs and amount of RAM. “Serverless” generally implies that you do not provision any server hardware (even virtual) and instead only provide application code.

I see your point, but we could view that as a quirk of the way they handle billing.

If the instance fails, you're insulated from that, right?

I’m no expert, but I think you run RDS on an EC2 instance, so it’s basically just a normal virtual server running Amazon’s managed version of the RDBMS. I’m not sure what happens if an instance “fails” but I assume you can have downtime if Amazon needs to move your VM, just like EC2, but I assume Amazon handles moving the instance and restarting it.

> I think you run RDS on an EC2 instance, so it’s basically just a normal virtual server running Amazon’s managed version of the RDBMS

Yes I think that's right. That is to say, it doesn't give you replication.

> I’m not sure what happens if an instance “fails” but I assume you can have downtime if Amazon needs to move your VM, just like EC2, but I assume Amazon handles moving the instance and restarting it.

No need for the quotation marks, that's the correct terminology. Your suspicions seem to be right on - it looks like RDS handles instance-failure for you, with non-trivial downtime, but no data-loss. [0]

https://aws.amazon.com/blogs/database/amazon-rds-under-the-h...