Just goes to show how much a single SQL server can scale before having to worry about sharing and horizontal scaling

Based on their stated 225M sites and a renewal period of 90 days, they're probably averaging around 40 certificates per second. That's only an order of magnitude higher than bitcoin; I wouldn't call it an indication of an ability to scale to a particularly large amount of traffic.

Yes. They are not doing a very heavy computational workload. Typical heavy-duty servers these days can do 100k's or millions of TPS. 40 TPS is a really, really, really light load.

Further, I was looking at those new server specs. There's an error I think? The server config on the Dell site shows 2x 8 GB DRIMMs, for 16 GB RAM per sever, whereas the article says 2 TB!

With only 16GB of RAM, but 153.6 TB of NVMe storage, the real issue here is memory limitation for a general-purpose SQL database or a typical high-availability NoSQL database.

Check my math: 153600 GB storage / 16 GB memory = 9600:1 ratio

Consider, by comparison that a high data volume AWS i3en.24xlarge has 60TB of NVMe storage but 768 GB of RAM. A 78:1 ratio.

If the article is correct, and the error is in the config on the Dell page (not the blog), and this server is actually 2 TB RAM, then that's another story. That'd make it a ratio of 153600 / 2000 = ~77:1.

Quite in line with the AWS I3en.

But then it would baffle me why you would only get 40 TPS out of such a beast.

Check my logic. Did I miss something?

Why are you assuming that their workload includes just one query per emitted certificate?

The reality is that they are storing information during challenges, implementing rate limiting per-account, supporting OCSP validation and a few other things.

You can investigate further if you really want to see the queries that they make against the database since their software (Boulder) is open source [1]. Most queries are in the files in the "sa" (storage authority) folder.

[1] https://github.com/letsencrypt/boulder/