Make faiss-cpu an optional dependency in v3.0.0

[dlqqq]

Problem

Listing faiss-cpu as a required dependency has caused numerous issues for users.

• Meta does not distribute any builds of FAISS. FAISS distributions on PyPI and Conda Forge are unofficially maintained by third-party contributors.
• On PyPI, we can only install FAISS via faiss-cpu, therefore we have faiss-cpu listed as a required dependency.
• However, installing faiss-cpu from Conda Forge does not install a Python package named faiss-cpu, but instead a Python package named faiss. This causes pip check to fail, since faiss-cpu is not installed. Jupyter AI still works however, since both packages provide the faiss module that we import.
• FAISS releases on PyPI and Conda Forge may lag behind the latest releases of FAISS on GitHub, as they are maintained by third-party contributors. This will limit the rate at which we can upgrade to new releases of Python, e.g. Python 3.13.

Proposed Solution

• Make faiss-cpu an optional dependency.
• Allow other vector databases to be used by /learn.
• Ideally, users should be able to install support for other vector databases at runtime, without requiring a restart of the Jupyter Server.

Additional context

• jupyter-ai v2.28.1 (removes post-link script) conda-forge/jupyter-ai-feedstock#47

[asadoughi]

Hi! Official FAISS builds are available via the conda pytorch channel: https://github.com/facebookresearch/faiss/blob/main/INSTALL.md

[krassowski]

Thanks for the link @asadoughi! However, asking all conda users of jupyter-ai to include pytorch channel might be a high bar. Some organizations only allow conda-forge (due to licensing concerns) and sometimes having multiple channels enabled will lead to conflicts in the binaries. I think it would be much easier to reconsider if the official distributions were mirrored in the conda-forge channel.

[krassowski]

Also, I understand that the pytorch channel is deprecated anyways, right?

• [Announcement] Deprecating PyTorch’s official Anaconda channel pytorch/pytorch#138506

[krassowski]

Taking liberty to mention @h-vetinari as the only listed maintainer on conda-forge feedstock for faiss (and also a frequent contributor to conda-forge/pytorch-cpu-feedstock it seems).

@asadoughi do you think that there would be a chance for the FAISS team to collaborate with @h-vetinari on getting the conda-forge feedstock back to speed given the deprecation of pytorch channel and that the pytorch team is directing users to conda-forge channel too:

We are directing users to utilize our official wheel packages from download.pytorch.org or PyPI, or switch to utilizing conda-forge (pytorch-cpu, pytorch-gpu) packages if they would like to continue to use conda.
[...]
As well, we have met with conda-forge maintainers and are looking to address any gaps that may be present in the pytorch-cpu / pytorch-gpu packages on conda-forge in order to make this move as seamless as possible for users.

[krassowski]

Allow other vector databases to be used by /learn.

I'm hearing a lot of good things about https://github.com/lancedb/lancedb, I wonder how much effort it would be to allow one or the other.

[h-vetinari]

Hey 👋

Faiss has fallen off the radar a bit, because it was quite a handful to maintain (...for free and with no feedback or help from anyone...). If it turns out to be useful, it's not a big deal to bring it back up to speed. There's further optimization work possible (e.g. doing AVX2 or AVX512-enabled builds), but for now I've kept it running. Just saw that the bot didn't open a PR for 1.9, that should be easy to fix. Any help on the feedstock from interested parties is more than welcome.

I'm hearing a lot of good things about https://github.com/lancedb/lancedb, I wonder how much effort it would be to allow one or the other.

Not involved there, but it has a healthy-looking feedstock in conda-forge.

[dlqqq]

@h-vetinari

Faiss has fallen off the radar a bit, because it was quite a handful to maintain (...for free and with no feedback or help from anyone...).

We really appreciate the effort you've put in to making faiss available on conda-forge! It's incredible that you've maintained it in your free time. The PyPI wheels are also being maintained by an external contributor, and also have a few issues.