Somebody please explain Aws serverless like I am a 5 year old.

Why the fuck are they talking about cold start time and completely reengineering the jvm so that they capture it after it is initialized?

Rube goldberg shit…

I am amazed at what they can do with minecraft modding. They inject code, textures, models, and the works to alter the way the game runs.

Think of it as spinning up a container per-request. That could be per API or web request, per cron request for a batch job, per file if you're triggering in S3 - but the key is a container spins up, from scratch, precisely whenever it's needed - then goes away again as soon as it's done. (I'm simplifying - cold / hot start means it's not always like that, but yaknow - 5 year old.)

This means that cold start time becomes *really* important, because now on every request, you're potentially starting a JVM and initialising all the libraries from scratch. A 10 second warmup time has virtually 0 impact in a classic K8s or hosted setting - but if you're doing that for each web request, it's beyond unacceptable. That's why there's a big push at the moment for fast startup tech like CRaC on the JVM level.

(Whether serverless lives up to the hype is another question, but ignoring that for now...)

amazon serverless:

it's just any other hosting, except you pay even more for even less control, and if you use it you probably already lost your marbles.

A container per request built on top of the stupid shit that the jvm does when it starts=putting 20 pounds of shit in a 10 pound bag. Yeah. My suspicions are confirmed. So we have to reengineer the jvm. Awesome.

You want a cookie.
You don’t want to bake a cookie.
You ask for a “readymade” cookie.
You can customise it, and it is baked by others.

That’s server-less. It is just someone else’s server that hooks into your code.

ChatGPT answer:

Imagine AWS serverless like a magical kitchen where you don't have to worry about cooking or cleaning up. You just tell the kitchen what you want to eat, and it appears on your plate, perfectly cooked, without you needing to do anything else. In the same way, AWS serverless lets you run your computer programs without having to worry about the computer (server) they run on. AWS takes care of everything, so you can focus on what your program needs to do. It's like magic for computers!

5 yo, that's going to limit the vocabulary too much and is different for each 5 year old. Can you read yet?

The idea of server less computing is that it's only running on each request/trigger.
For efficiency it's kept running a bit so the next trigger/request does not incur the startup time every single time. Now the problem with Java is that it's not really suited for this model all the startup times can be huge, request timeout huge. To not always have an instance running (and general peak auto horizontal scaling) they are working on decreasing this startup time.

@AlmondSauce just read your comment. You are already describing it really well. Only thing I would like to point out is that it does matter on k8s too when it comes to horizontal scaling. If you get a burst of traffic and I takes 10 seconds extra the shit is already hitting the fan. I've seen this mitigated a bit by pre scaling in anticipation. Defeating the purpose of auto scaling a bit.

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