Show HN: Zedis – A Redis clone I'm writing in Zig

https://github.com/barddoo/zedis

by barddoo • 10 months ago

158 111 10 months ago

github.com

Writing Redis from scratch in Zig.

pdntspa2• 10 months ago

Is zig lang stable enough now to start basing real projects on it?

justinhj4• 10 months ago

Check out Tigerbeetle and Ghostty

jrpelkonen• 10 months ago

Also bun

fishmicrowaver• 10 months ago

I mean no offense but a billionaires vanity terminal and a database with an anime bug mascot are a bit different than a redis alternative

tonyhart7• 10 months ago

"Is zig lang stable enough now to start basing real projects on it?"

only if you want to refactor/rewrite a lot

barddoo16• 10 months ago

The standard library is changing too much to be honest. During the development of the library Zig 0.15 launched and changed the whole Io library.

pyrolistical• 10 months ago

Depends on your definition of stable. I would suspect most people would consider it unstable as they are still breaking the API for async. Wait for 1.0 if you really need true stability. But zig is just so good not to use now

nitishr2• 10 months ago

it hasn't reached version 1.0

tcfhgj• 10 months ago

So riiR is now riiZ? ;)

nine_k4• 10 months ago

"Rewrite it away from C (or C++)". Whether you choose Rust, Zig, Ada, D, Nim, even Pascal, it's likely going to become more secure. It will be supported on fewer platforms though, but still should run fine under Linux, macOS, Windows, *BSD, on x64, Arm64, and likely RISC-V, too.

maleldil3• 10 months ago

Zig isn't memory safe, though. It's safer than C or C++, but not much.

johnisgood7• 10 months ago

Seems like LLMs are getting good at Zig (with some help, I presume).

mtlynch• 10 months ago

Is there anything about this project that seems LLM-generated?

I've found that LLMs are particularly bad at writing Zig because the language evolves quickly, so LLMs that are trained on Zig code from two years ago will write code that no longer compiles on modern Zig.

5-• 10 months ago

https://github.com/barddoo/zedis/blob/87321b04224b2e2e857b67...

these seem to occur only in college assignment projects, and in the output of text generators trained on those.

rmonvfer• 10 months ago

As an avid Claude Code user, I can tell you with 99% probability, that README is LLM-generated. This exactly the same structure and wording used by Claude (of course, it has some human modification because otherwise I’d filled with emojis)

In my experience, when you work with something like agentic development tools, you describe your goals and give it some constraints like “use modern zig”, “always run tests”… and when you ask it to write a README, it will usually reproduce those constraints more or less verbatim.

The same thing happens with the features section, it reads like instructions for an LLM.

I might be wrong but I spend way too much time using Claude, Gemini, Codex… and IMHO it’s pretty obvious.

But hey, I don’t think it’s a problem! I write a lot of code using LLMs, mostly for learning (and… ejem, some of it might end up in production) and I’ve always found them great tools for learning (supposing you use the appropriate context engineering and make sure the agent has access to updated docs and all of that). For example, I wanted to learn Rust so I half-vibed a GPUI-based chat client for LLMs that works just fine and surprisingly enough, I actually learned and even had some fun.

jasonjmcghee3• 10 months ago

I skimmed, for me it was this: https://github.com/barddoo/zedis/blob/87321b04224b2e2e857b67...

There seems to be a fair amount of stigma around using llms. And many people that use them are uncomfortable talking about it.

It's a weird world. Depending on who is at the wheel, whether an llm is used _can_ make no difference.

But the problem is, you can have no idea what you're doing and make something that feels like it was carefully hand-crafted by someone - a really great project - but there are hidden things or outright lies about functionality, often to the surprise of the author. Like, they weren't trying to mislead, just didn't take them time to see if it did all of what the LLM said it did.

johnisgood7• 10 months ago

Fair enough, but I have made a couple of projects in Odin using Claude, and Odin is evolving too, and it is much more obscure than Zig. I made these projects successfully by feeding the LLM the documentation of Odin and gave it example projects... thus, if I could create Odin projects (with some reiterations and hand-holding, true), then Zig should be even better.

barddoo16• 10 months ago

Oh that’s nice of you. I take that as a compliment.

johnisgood7• 10 months ago

It was not intended to be a criticism. I care about the end result, not the process. I use LLMs myself, too.

esafak• 10 months ago

Consider adding support for vector search and sketching (https://www.sketchingbigdata.org/).

barddoo16• 10 months ago

I'll take a look. Thanks for the suggestion!

jasonjmcghee3• 10 months ago

I'm not really sure what it costs these days - i know certain projects not entirely free like they were a few years ago, but there's a pretty good "build your own redis" among other things.

It has little step-by-step tasks with automated tests. There are some other good ones like git and docker. It's pretty cool.

https://app.codecrafters.io/courses/redis/overview

nine_k4• 10 months ago

It's easy to write a KV store, even a KV store with key expiration. But Redis is quite a bit more than that. Consider sharding and replication at least. Then lists, sets, zsets, bitfields, streams, geospatial indexes, hyperloglog / bloom filters, time series.

Something like LevelDB is relatively easy to write. Then you can build the rest of Redis on top of it.

johnisgood7• 10 months ago

Then lists, sets, zsets, bitfields, streams, geospatial indexes, hyperloglog / bloom filters, time series.

I mean, I have my own C libraries for most of these!

barddoo16• 10 months ago

Sounds pretty interesting.

nitishr2• 10 months ago

Are you keeping it single threaded?

barddoo16• 10 months ago

No, I wasn’t able to get it working with async io using io_uring/kqueue.

maleldil3• 10 months ago

From the README:

Memory safety with RAII patterns

I'm curious to see how they achieve RAII in Zig, which doesn't have destructors. If they mean defer + deinit methods, that's not the same thing.

justinhj4• 10 months ago

Zig is all about making things explicit. Destructors are hidden code. I presume there will be an application level tracking of lifetime.

maleldil3• 10 months ago

Yes, which is why Zig can't have RAII. Zig initialisation and destruction are fundamentally different to how RAII works in other languages. That's not a negative point; it's just how Zig is. But it's not RAII.

teo_zero• 10 months ago

If they mean defer + deinit methods, that's not the same thing.

No? It's the first thing that came to my mind when I've read RAII.

rokob• 10 months ago

You have to call defer after initialization so you can’t technically call it RAII. As long as you remember to call it then it is effectively the same. Personally defer makes it so very similar to be a difference without a distinction but the “is initialization” part can’t be true if you need to do a second step.

BiraIgnacio• 10 months ago

cool stuff, keep at it!

barddoo16• 10 months ago

Thanks! There are so many things to do still, authentication, glob-style keys search, json parsing.

znpy2• 10 months ago

OT: Reminds me of the late 2000s when python was having its boom and it was a lot of pythis and pythat

barddoo16• 10 months ago

I just made it to learn Zig

znpy2• 10 months ago

Oh yeah absolutely, i wasn’t bashing you in any way! Well done!

reenorap• 10 months ago

This is an interesting project but a poorly chosen name because it can easily be considered trademark infringement for being confusingly-similar to "Redis", especially since it's a self-admitted clone. I would change it now before you are forced to change your name and you lose time confusing people and wasting time renaming everything.

saghm• 10 months ago

I don't think it's particularly confusing. I wouldn't expect something official to have a name that changes the first letter. Would you honestly be confused about whether a search engine called Boogle, a laptop called a Yacbook, or a browser called Tirefox was an official product by Google, Apple, or Mozilla?

thewisenerd• 10 months ago

i think “$proj - implements the redis protocol” are going to be as ubiquitous as the things which claim to be “S3 compatible”

idk if redis labs (the organization aka big bad) are going to patent the “protocol” to disallow clones (or they’d be going after valkey first)

barddoo16• 10 months ago

That’s a good point, I should had renamed it. You can’t trust these big corp

jiehong• 10 months ago

I’d see it in swift and then being called "Swedish" for giggles.

Naming is famously difficult in this world!

k_bx4• 10 months ago

Sorry if somewhat off-topic, but might help with getting more users. Redis is actually good enough and easy to install for most projects, but it has downside that it's "memory-only" (needs to fit in ram), and if you're in a tight container/vm – you'd better not rely on it solely.

So, there's another project – called kvrocks https://github.com/apache/kvrocks , which is for people which don't need in-memory perf of redis but would like to use its protocol and be still very performant. However, its devs never packaged a release in deb and other formats.

So, if you were to implement something similar ^ which will implement the protocol, have ability to grow on disk, and be available in distro repos (ideally) – would definitely hold a niche of many little projects which benefit from redis-like thing I've done.

jasonjmcghee3• 10 months ago

fwiw redis has persistence https://redis.io/docs/latest/operate/oss_and_stack/managemen...

lyu072822• 10 months ago

That just makes it durable, the entire dataset still has to fit in memory.

Szpadel• 10 months ago

Redis is for high frequency cache, disk latencies would slow it too much. Maybe putting something that would normally be evicted to disk could be valid compromise.

another major drawbacks of Redis is that It is single threaded and sync. you need expensive high frequency CPU if you need more performance. something that could benefit from multi core system and if you would want to use disk cache async is a must. single threading also affects scripts running on Redis side, when they execute whole Redis is waiting and is unable to fulfil other requests.

another place for improvement would be proper easier to use HA, and maybe also auto scaling.

k_bx4• 10 months ago

Most projects need to start with something and know that they will "be good". Many will hit RAM limitations earlier than kvrocks latencies or single-threaded CPU limitations (if they will – usually author doesn't need advice). Most would benefit from "moving fast" (in terms of development).

Redis-compatible protocol guarantees that you can think about the things you've mentioned later. If project is successful – you'll find money to pay for RAM and move to pure Redis. If it's CPU-bound – you'll find multi-threaded alternatives.

So this is a pretty nice niche IMO actually.

progbits• 10 months ago

The Redis HA story is horrendous. I wonder if Sentinel is intentionally just crap enough to get your application locked in but then force you to pay them for hosted option.

It regularly gets itself into messed up state and even with graceful shutdown for node updates the official client libraries throw errors for up to a minute.

ncruces• 10 months ago

Redka may be interesting to you: https://github.com/nalgeon/redka

barddoo16• 10 months ago

I didn’t know that, that’s pretty cool

badLiveware• 10 months ago

Redis compatible projects with larger-than-memory support do exists, e.g. https://microsoft.github.io/garnet/docs/welcome/features#tie...

k_bx4• 10 months ago

No apt repo, C#.. kinda worse than kvrocks in that sense

nine_k4• 10 months ago

If you're in a tight VM and are running Redis inside it, as opposed to a separate VM / cluster, you need an embedded DB, not Redis.

You can use the ancient BerkeleyDB which is supported everywhere for last like 30 years. Or a more recent LevelDB. Or even SQLite which is plenty fast on simple queries.

You'll have to tolerate the high latency of safely writing tings to a block device, compared to RAM. If your load is mostly reads, it should be OK.

era37• 10 months ago

Looks like a cool project; does the project aim to fix anything existing about Redis or is this just a fun side project? Thanks

barddoo16• 10 months ago

Redis dynamically allocates memory, the idea of the project is to pre allocate everything, so it’s by principle faster than Redis.

didip• 10 months ago

What about calling it Zigdisk and make it save to disk?

mawadev• 10 months ago

This is a very cool project. I wish it could do the same stuff as RedisJson at some point!

barddoo16• 10 months ago

I definitely plan to do that in the future

montyanderson• 10 months ago

gkorland• 10 months ago

Did you try to run redis-benchmark? (Compared to Redis)

destroycom• 10 months ago

Written in Zig for optimal performance and memory safety

Ironic to see this, as even a cursory glance over the code shows a lot of memory bugs, such as dangling pointers, data races, some potential bugs like double free, etc.

It is good that the OP is learning things, but I would caution against relying on LLMs and taking on a bigger project like this, before the basics are well understood.

Personally, this is one of the reasons I dislike the LLM hype, people are enabled to produce much more code, code that they aren't qualified to support or even understand.

While the project linked is clearly designated as strictly for "learning purposes", the applications we will get in the large will be of no better quality.

The difference being, before LLMs, those, who didn't have qualification, wouldn't even approach problems like this, now they can vibecode something that works on a lucky run, but is otherwise completely inadequate.

glouwbug• 10 months ago

I think this is the most apt summary of LLMs I’ve seen to date

Show HN: Zedis – A Redis clone I'm writing in Zig

Related Stories