mlrd: DynamoDB-Compatible API on MySQL

Introducing mlrd (“mallard”) to the world: a DynamoDB-compatible API on MySQL. Crazy, but it works really well and I’m confident it will help a lot of businesses save a lot of money. Here’s why.

Preamble

Let me be clear about two things from the start:

1. mlrd is not free open source; it’s a commercial database tool. Why, after 20 years of publishing free open source tools? Two reasons. First, because I have bills to pay, too. Second, because you can somewhat reverse engineer mlrd. Emphasis on “somewhat” because a complete solution like mlrd is a lot more difficult than it seems.

2. Amazon DynamoDB is a great database product. It really is an engineering marvel. If you’re using it and happy with it (all aspects, from its costs to its single-vendor nature), then great! Stop reading and keep using it.

Problems and Progress

mlrd solves three problems:

1. DynamoDB costs can easily skyrocket out of control
2. Vendor lock-in
3. Data hostages

The first two are plain and obvious to anyone using DynamoDB beyond trivial tables.

The third was what kept me motivated and going while I programmed mlrd all by my lonesome: once you put your data into DynamoDB, there is absolutely no way to get it back without paying AWS a little something. DynamoDB holds your data hostage.

As someone practically born into the world of open source and the good/positive/legal computer hacker ethos, I couldn’t ignore this. And being a hacker, I tried to find a loophole, a trick, a hack—some way to access data in DynamoDB without paying a single RCU.

I couldn’t find one.¹

So I have to hand it to AWS: their DynamoDB billing is airtight. And in their (AWS) defense, DynamoDB table dumps are relatively cheap: $0.10 per GB plus PITR costs.

But a hostage is hostage no matter how small the ransom demand.

mlrd doesn’t just free the data hostages, it shatters the vendor lock-in, too.

For example, once you put mlrd between your app and DynamoDB, since mlrd speaks the DynamoDB protocol and knows all the DynamoDB nuances, you can freely write items to MySQL as they’re read or written in DynamoDB. (“Freely” means paying no extra RCUs or WCUs. If your MySQL is also on AWS, that could incur read/write costs.)

Security Scanning

A really good practical example and use case that mlrd enables without breaking the bank is security scanning.

Some companies proactively scan data to make sure devs didn’t accidentally store sensitive data, PII, and so on. But how do you do this in DynamoDB without paying more RCUs or CDC costs? In DynamoDB you cannot.

But with mlrd you can because, as noted above, mlrd gives you free access to your data. Some companies will use mlrd for no other reason than to freely inspect their data.

mlrd can do a lot more than this, but as long as it’s helping companies make progress, then all those hours spent talking to myself while coding it will be worth it.

Costs

I don’t know yet how mlrd will be priced, but as a private pico-sized corporation, I expect it will be miniscule compared to the millions of dollars some companies pay for DynamoDB.

The real question is: what does MySQL cost you?

If you’re running bare metal, you’re in luck! Bare metal enterprise hardware plateaued a few years ago. For example, years ago 32 cores and 256 GB RAM were common. Today, I have a few 1U servers like that (and more powerful) in my basement, and they were cheap.

What would cost me $100,000/year on DynamoDB costs me zero—yeah, $0—to run in my basement.²

“Oh come on, Daniel! You know that DynamoDB is highly resilient and highly available! Your basement servers are just loud toys.”³

Yeah, maybe.

You can’t run your business from my basement, but you can literally bank on PlanetScale. When you contact me to discuss mlrd in more detail, I’ll show you PlanetScale + mlrd can be 40–60% cheaper than DynamoDB.

Private Beta

Check out the 2 minute video at https://mlrd.tech.

No AI slop; just me, my laptop, and my servers.

If you/your company has these problems, get in touch and let’s see if mlrd can help fix them.