> Most large SaaS companies can run off of $5k / m or cheaper RDS
Hard disagree. An r6i.12xl Multi-AZ with 7500 IOPS / 500 GiB io1 books at $10K/month on its own. Add a read replica, even Single-AZ at a smaller size, and you’re half that again. And this is without the infra required to run a load balancer / connection pooler.
I don’t know what your definition of “large” is, but the described would be adequate at best at the ~100K QPS level.
RDS is expensive as hell, because they know most people don’t want to take the time to read docs and understand how to implement a solid backup strategy. That, and they’ve somehow convinced everyone that you don’t have to tune RDS.
If you're not using GP3 storage that provides 12K minimum IOPS without requiring provisioned IOPS for >400GB storage, as well as 4 volume striping, then you're overpaying.
If you don't have a reserved instance, then you're giving up potentially a 50% discount on on-demand pricing.
An r6i.12xl is a huge instance.
There are other equivalents in the range of instances available (and you can change them as required, with downtime).
For MySQL and Postgres, RDS stripes across four volumes once you hit 400 GiB. Doesn't matter the type.
The latency variation on gp3 is abysmal [0], and the average [1] isn't great either. It's probably fine if you have low demands, or if your working set fits into memory and you can risk the performance hit when you get an uncached query.
12K IOPS sounds nice until you add latency into it. If you have 2 msec latency, then (ignoring various other overheads, and kernel or EBS command merging) the maximum a single thread can accomplish in one second is (1000 msec / 1 sec / 2 msec) = 500 I/O. Depending on your needs that may be fine, of course.
> If you don't have a reserved instance, then you're giving up potentially a 50% discount on on-demand pricing.
True, of course. Large customers also don't pay retail.
> An r6i.12xl is a huge instance.
I mean, it goes well past that to .32xl, so I wouldn't say it's huge. I work with DBs with 1 TiB of RAM, and I'm positive there are people here who think those are toys. The original comment I replied to said, "large SaaS," and a .12xl, as I said, would be roughly adequate for ~100K QPS, assuming no absurdly bad queries.
Hard disagree. An r6i.12xl Multi-AZ with 7500 IOPS / 500 GiB io1 books at $10K/month on its own. Add a read replica, even Single-AZ at a smaller size, and you’re half that again. And this is without the infra required to run a load balancer / connection pooler.
I don’t know what your definition of “large” is, but the described would be adequate at best at the ~100K QPS level.
RDS is expensive as hell, because they know most people don’t want to take the time to read docs and understand how to implement a solid backup strategy. That, and they’ve somehow convinced everyone that you don’t have to tune RDS.