Saving another 100TB of RAM
103 points by f311a 3 hours ago | 19 comments
proc0 44 minutes ago
The only Rust section is the one on storage improvements about the struct that stores the hash, but do they really need that many hashes that 2 bytes makes that big of a difference? Article doesn't expand, but I guess it's a hash for every task on every computer, so maybe yes.
replyagosta 45 minutes ago
Bang up article! As someone who doesn't get to do enough (almost any) calculus in my daily programming assignments, I thoroughly enjoyed reading about Kevin's dive into that derivation (linked in the supplemental article). All the people being negative here can swallow raisins
replyofficialchicken 60 minutes ago
Come on CF, you can't even be bothered vibe a README for the crate? Somebody tear down this post until this garbage is documented properly.
replyI found this in the code, it looks like a rewrite-in-rust:
//! # pingora-ketama
//! A Rust port of the nginx consistent hashing algorithm.
//!
//! This crate provides a consistent hashing algorithm which is identical in
//! behavior to [nginx consistent hashing](https://www.nginx.com/resources/wiki/modules/consistent_hash...).
//!
//! Using a consistent hash strategy like this is useful when one wants to
//! minimize the amount of requests that need to be rehashed to different nodes
//! when a node is added or removed.
globnomulous 5 minutes ago
If you have a real, actual, substantive critique of either the post or package itself, I'd be interested in reading that. What you posted doesn't provide that. I'm not sure who you're talking to or what you expect your comment to accomplish.
replycyberpunk 44 minutes ago
Anyone have an idea how it behaves differently from google's jump hash algorithm? The cool thing about google's one is it's so short I can include it in a HN comment:
reply int32_t JumpConsistentHash(uint64_t key, int32_t num_buckets) {
int64_t b = 1, j = 0;
while (j < num_buckets) {
b = j;
key = key * 2862933555777941757ULL + 1;
j = (b + 1) * (double(1LL << 31) / double((key >> 33) + 1));
}
return b;
}
cyberpunk 31 minutes ago
Well I looked it up; nginx, apparently, uses ketama -- it's a ring-style hash probably works better for web backends than the jch above, as when given [0,1,2,3] and replacing the server in slot 1 you're going to have a lot of hash moves. With ketama, you'd only have the '1' hashes moving. You can't really beat google's for brevity, though.
replyagosta 49 minutes ago
We can tell you didn't read the post because it is definitively NOT garbage. Very interesting write up by the Cloudflare team - the man literally did calculus to improve something. When's the last time any of us did Calculus to improve anything? Bang up job Kevin and everyone!!
replygo_elmo 2 hours ago
Was this vibecoded? I hope so, would expect models to be good enough by now, its not that creative.
replyMaxion 2 hours ago
I think it's more important now than it was last year to differentiate pure yolo vibecoding from "AI assisted engineering" or "AI engineering", I.e. deliberate and careful use of AI to speed up coding but without creating too much slop. Maybe aineering?
replyreadthenotes1 2 hours ago
I expect a another post in a year where they get a performance improvement by reducing the number of calls to create integers from bytes.
reply
One wants to turn on an indicator on a remote device. A simple Boolean value. But we need networking, TLS, authentication plugins, certificate validation, distributed logging, containers, orchestration, HTTP client/server, interprocess communication, daemon dependency management, …
Sure, one can say each of these layers and abstractions has an important and justifiable purpose. But one can also step back and start wondering - what the hell are we really doing???
At some level, it seems like each layer of abstraction has to manage others, only simply because they exist.
Imagine the simplicity of 1800s telegraph signaling - no software!
Too often we build systems with Fortune-50 style hierarchies when a 5-person team could do the whole job.