693: use the lmdb-master.3 branch r=Kerollmops a=irevoire
After investigating https://github.com/meilisearch/meilisearch/issues/3017, we found out that it was due to lmdb and that, without any code change on our side, bumping using the lmdb-master-3 branch fix our issues.
But, we’re not really confident about what changed between the `mdb.master` and `mdb.master3` branches; thus this is a temporary change, and we hope we’ll be able to move to the new version of heed asap (either before the end of the pre-release or for the next release).
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The bug is hard to reproduce; I can reproduce it 100% of the time on my archlinux personal computer. But on a scaleway archlinux bare-metal machine, it doesn’t reproduce. It’s flaky on our test suite, but `@loiclec` was able to write a minimal test that reproduces it every time on macOS.
Basically, what happens is when there are multiple threads opening databases in a different directory at the same time.
If there are 10 or more threads running at the same time, lmdb starts throwing the `Invalid argument (os error 22)` error for no reason, we believe.
I would like to submit an issue to lmdb, but I don’t really have the time to write a test in C without heed currently.
`@hyc,` if you want to take a look at it, here is the repo that reproduces the issue on macOS: https://github.com/irevoire/heed-bug
Co-authored-by: Irevoire <tamo@meilisearch.com>
e.g. add one facet value incrementally with a group_size = X and then
add another one with group_size = Y
It is not actually possible to do so with the public API of milli,
but I wanted to make sure the algorithm worked well in those cases
anyway.
The bugs were found by fuzzing the code with fuzzcheck, which I've added
to milli as a conditional dev-dependency. But it can be removed later.
635: Use an unstable algorithm for `grenad::Sorter` when possible r=Kerollmops a=loiclec
# Pull Request
## What does this PR do?
Use an unstable algorithm to sort the internal vector used by `grenad::Sorter` whenever possible to speed up indexing.
In practice, every time the merge function creates a `RoaringBitmap`, we use an unstable sort. For every other merge function, such as `keep_first`, `keep_last`, etc., a stable sort is used.
Co-authored-by: Loïc Lecrenier <loic@meilisearch.com>
We need to store all the external id (primary key) in a hashmap
associated to their internal id during.
The smartstring remove heap allocation / memory usage and should
improve the cache locality.
436: Speed up the word prefix databases computation time r=Kerollmops a=Kerollmops
This PR depends on the fixes done in #431 and must be merged after it.
In this PR we will bring the `WordPrefixPairProximityDocids`, `WordPrefixDocids` and, `WordPrefixPositionDocids` update structures to a new era, a better era, where computing the word prefix pair proximities costs much fewer CPU cycles, an era where this update structure can use the, previously computed, set of new word docids from the newly indexed batch of documents.
---
The `WordPrefixPairProximityDocids` is an update structure, which means that it is an object that we feed with some parameters and which modifies the LMDB database of an index when asked for. This structure specifically computes the list of word prefix pair proximities, which correspond to a list of pairs of words associated with a proximity (the distance between both words) where the second word is not a word but a prefix e.g. `s`, `se`, `a`. This word prefix pair proximity is associated with the list of documents ids which contains the pair of words and prefix at the given proximity.
The origin of the performances issue that this struct brings is related to the fact that it starts its job from the beginning, it clears the LMDB database before rewriting everything from scratch, using the other LMDB databases to achieve that. I hope you understand that this is absolutely not an optimized way of doing things.
Co-authored-by: Clément Renault <clement@meilisearch.com>
Co-authored-by: Kerollmops <clement@meilisearch.com>
402: Optimize document transform r=MarinPostma a=MarinPostma
This pr optimizes the transform of documents additions in the obkv format. Instead on accepting any serializable objects, we instead treat json and CSV specifically:
- For json, we build a serde `Visitor`, that transform the json straight into obkv without intermediate representation.
- For csv, we directly write the lines in the obkv, applying other optimization as well.
Co-authored-by: marin postma <postma.marin@protonmail.com>
384: Replace memmap with memmap2 r=Kerollmops a=palfrey
[memmap is unmaintained](https://rustsec.org/advisories/RUSTSEC-2020-0077.html) and needs replacing. memmap2 is a drop-in replacement fork that's well maintained. Note that the version numbers got reset on fork, hence the lower values.
Co-authored-by: Tom Parker-Shemilt <palfrey@tevp.net>
