Comment by chamomeal | Hacker News Reader

Comment by chamomeal | Hacker News Reader

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Idk I think caching is a crucial part of many well-designed systems. There’s a lot of very cache-able data out there. If invalidating events are well defined or the data is fine being stale (week/month level dashboards, for example), that’s a fantastic reason to use a cache. I’d much rather just stuff those values in a cache than figure out any other more complicated solution.

I also just think it’s a necessary evil of big systems. Sometimes you need derived data. You can even think about databases as a kind of cache: the “real” data is the stream of every event that ever updated data in the database! (Yes this stretching the meaning of cache lol)

However I agree that caching is often an easy bandaid for a bad architecture.

This talk on Apache Samza completely changed how I think about caching and derived data in general: https://youtu.be/fU9hR3kiOK0?si=t9IhfPtCsSyszscf

And this interview has some interesting insights on the problems that caching faces at super large scale systems (twitter specifically): https://softwareengineeringdaily.com/2023/01/12/caching-at-t...

Caching is definitely a useful and even a key component to producing efficent and high performance applications and services.

I think the mistake is not using caching, but rather using it too soon in the development process.

There are times when caching is a requirement because there is simply no way to provide efficient performance without it, but I think too many times developers jump straight to caching without thinking because it solves potential problems for them before they happen.

The real problem comes later though at scale when caching can no long compensate for the development inefficiencies.

Now the developers have to start rewriting core code which will take time to thoroughly complete and test and/or the engineers have to figure out a way to throw more resources at the problem.

There are a lot of things necessary to be a successful human but doing them without doing the fundamentals just makes you a monkey in a suit.

Caching belongs at the end of a long development arc. And it will be the end whether you want it too or not. Adding caching is the beginning of the end of large architectural improvements, because caches jam up the analysis and testing infrastructure. Everything about improving or adding features to the code slows down, eventually to a crawl.

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