kero

Co-founder & CTO @meilisearch. Rust developer and ex-student from @42born2code.

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npub1xyypr4cduzmn6zwx9yuxjq2utyhrdnxpjz422pxc6y0hwaa652uqmy6vyg

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kero@fosstodon-org.mostr.pub

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nprofile1qqsrzzq36ux7pdeap8rzjwrfq9w9jt3kenqep249qnvdz8mhw7a29wqpz4mhxue69uhhyetvv9ujumt0wd68ytnsw43qzrmhwden5te0dehjuum5wghxxus3fmqrk

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npub1xyypr4cduzmn6zwx9yuxjq2utyhrdnxpjz422pxc6y0hwaa652uqmy6vyg

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Last Notes

2025-06-30 06:13:35 UTC

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@nprofile…2cpy 600 lignes and most of it is boilerplate? That seems ok to me. However, you're right, they probably have good reasons: unshared benchmarks.

2025-06-29 17:47:32 UTC

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@nprofile…2cpy yeah, you're right. The OS will load pages as needed and the only thing that changes now is the page format (leaf and overflow pages). However, this take you quote still need actual benchmarks. Tomorrow, I could also right a 10 word tweet saying the opposite...

2025-06-29 09:56:01 UTC

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@nprofile…2cpy I don't know but there are some missing benchmarks here. Anyway, I don't think it's untrue as I think using Go to perform direct C calls requires more CPU operations due to the syscalls not having the right "shape" (stack and registers). Go needs to switch to C-mode or something because they have their own function calling format to support out-of-the-box green threading 🤔

2025-06-18 07:16:38 UTC

https://trifectatech.org/blog/bzip2-crate-switches-from-c-to-rust/

2025-06-10 09:06:34 UTC

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@nprofile…2cpy generated by AI (claude code it seems). CI is broken, and they are not even using the latest version of heed (0.22)... I'll probably never try this tool on any production database at Meilisearch...

2025-05-10 08:07:39 UTC

Hey @nprofile…2cpy 👋 I wrote you there to ask you about LMDB intrinsics. Can you answer there, please? It's about being able to process database entries in parallel. https://github.com/meilisearch/heed/pull/334

2025-03-29 12:02:48 UTC

It happened! @meilisearch.com reached 50k stars on GitHub 🤩 we are still the second most-started search engine. Elasticsearch, we are coming for you. #rustlang
https://cdn.fosstodon.org/media_attachments/files/114/245/614/490/099/566/original/19c1d09c8e3a0386.png

2025-03-20 15:20:12 UTC

Today is a sad day 🥺 We will no longer use bors and switch to GitHub Merges Queues on @meilisearch.com. #rustlang https://github.com/meilisearch/meilisearch/pull/5447

2025-03-18 22:27:06 UTC

@nprofile…293t, I just read your original article about using c2rust to convert bzip2 to Rust, and I was wondering if you would recommend it to convert the LMDB source code. It does a lot of platform-specific operations, but it is also quite small (mdb.c, lmdb.h, mild.c, and mild.h only). Do you have more information than me on the converting tool from C to safe Rust? https://arxiv.org/abs/2412.15042

2025-03-18 16:50:44 UTC

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> working on a rust language experiment
What do you mean by that? Will it be a macro or something more deep that modifies the compiler with keywords and gotos?

2025-03-18 11:18:47 UTC

Hey @nprofile…293t, I am reading your recent article on zlib-rs, "zlib-rs is faster than C," and I was wondering if you tried to use the fallthrough libraries proposed at the end of this article to fill the Rust switch syntax gap? https://huonw.github.io/blog/2025/03/rust-fallthrough/

2025-03-17 16:53:16 UTC

We have worked hard on Meilisearch for the last 2 years and have cooked you smt amazing! We mixed chocolate and some AI toppings to release Hybrid Search, something new on the market. Be ready and subscribe to our upcoming Product Hunt event 🛎️
https://www.producthunt.com/products/meilisearch-cloud
https://cdn.fosstodon.org/media_attachments/files/114/178/811/077/609/494/original/87ae9a4e1f43b3a9.png

2025-03-15 10:15:20 UTC

Just released heed & heed3 v0.22, my Rust #lmdb wrapper, which improves the doc, supports dup sort custom comparators, support the PREV_SNAPSHOT flag, better support RoTxn with TSL, and use the latest LMDB version. Meilisearch is already using it! Go star it 🌟 https://github.com/meilisearch/heed/releases/tag/v0.22.0

2025-03-15 10:14:48 UTC

Just released heed & heed3 v0.22, my Rust LMDB wrapper, which improves the doc, supports dup sort custom comparators, support the PREV_SNAPSHOT flag, better support RoTxn with TSL, and use the latest LMDB version. Meilisearch is already using it! Go star it 🌟 https://github.com/meilisearch/heed/releases/tag/v0.22.0

2025-03-10 09:14:42 UTC

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@nprofile…2cpy I don't understand your point about libraries aborting a process. LMDB does precisely that in case an assertion is not valid. Panicking is the same thing as the mdb_cassert function being run in non-debug programs. The main difference is that panics can be watched in #Rust. You can see an example in Meilisearch: Sometimes, users have disk corruptions, and LMDB aborts the process. Shouldn't it return an MDB_PANIC error instead?
https://cdn.fosstodon.org/media_attachments/files/114/137/362/828/227/516/original/cefeba2f07d5266f.png

2025-02-26 18:06:56 UTC

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@nprofile…2cpy nice, based on heed3 my wrapper over LMDB with encryption-at-rest support 💪 Everything is Rust idiomatic and well documented.

2025-02-26 12:05:28 UTC

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@nprofile…2cpy I'm not only talking about the superior performances of the Rust impl but mainly about the memory safety of it and the non-performance-loss of it. So, why not using the safe one when there are no downside to do that? This paper from Inria x Microsoft also shows that using Rust is safer and doesn't impact performances. https://arxiv.org/abs/2412.15042

2025-02-26 08:56:20 UTC

Rust is the future, that's it! https://www.phoronix.com/news/Zlib-rs-0.4.2

2025-02-19 08:24:35 UTC

@nprofile…2cpy Hey 👋 I am wondering if you could fix LMDB by applying my patch because it no longer compiles on macOS due to the F_FULLSYNC non-existing macro. If you don't, I'll have to patch the compilation of LMDB in heed to alias F_FULLFSYNC with F_FULLSYNC. https://bugs.openldap.org/show_bug.cgi?id=10296#c6

2025-01-15 18:59:10 UTC

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@nprofile…2cpy I love reading this kind of news! It's just showing that we did the right choice at Meilisearch 👏

2024-06-10 22:02:02 UTC

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@npub13j3…fq0x it was a joke, actually! It's because we are THE tool that Apple could have used to do the RAG for their new Apple Intelligence software 🙃

2023-12-01 18:59:00 UTC

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@npub1kzt…guag Thanks for helping us with the SIMD-optimized distance functions ☺️

2023-08-14 09:17:19 UTC

Hey @npub1y0e…mm9n, we want to, zero-downtime swap an #LMDB environment that comes from an S3 with one that is already on disk (and opened). My first idea was to open the incoming env, open a write txn on the dst one and clear and copy the entries into the existing one but I fear about the MDB_TXN_FULL error. The second idea is to close the env (awaiting running txns) and swap the env files. This can produce a downtime. Do you recommend anything else?

2023-08-08 10:50:24 UTC

I don’t know when but I’ll probably ban people making me loose time by using incompetent LLM’s to code… Here is an example contributor using ChatGPT to work on my #LMDB Rust wrapper… But the documentation is clear. https://github.com/meilisearch/heed/pull/201#discussion_r1286562660

2023-08-06 21:41:59 UTC

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@npub1zea…rzh5 @npub15s5…xszk Unfortunately, lmdb-rkv is always above heed on lib.rs, even if it's no more maintained... https://lib.rs/search?q=lmdb

2023-08-06 21:05:15 UTC

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@npub1acg…p35c @npub1xts…kk5s Would be better if reproduced from scratch in C but if you know the last operation that corrupts the database maybe do this last one in C if possible. Providing the pre-corrupted database and the last operations breaking it could probably help diagnosis.

2023-08-06 20:36:46 UTC

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@npub15s5…xszk Just go with #LMDB. Only a single file, faster than SQLite for key-value storage and zerocopy read. I maintain a Rust wrapper called heed and Meilisearch is running on too of that, works perfectly 🎉
I recently updated the Wikipedia page. https://en.wikipedia.org/wiki/Lightning_Memory-Mapped_Database

2023-08-06 20:20:49 UTC

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@npub1acg…p35c @npub1xts…kk5s
I worked on bringing the DUPSORT LMDB feature to heed today. I will continue with the DUPFIXED later. I will release a new alpha version later next week, probably 🙂 https://github.com/meilisearch/heed/pull/200

2023-08-03 08:22:07 UTC

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@npub1acg…p35c @npub1xts…kk5s If you need anything, tell me, create an issue and I will see if I have time to work on it. I am working on this big v0.20 alpha refactor so let’s break everything 🏺

2023-08-02 21:51:52 UTC

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@npub1xts…kk5s @npub1acg…p35c I advise you to use heed that I maintain. We use it in Meilisearch. You should try the latest v0.20-alpha versions. https://lib.rs/crates/heed