Add asynchronous support to WeaviateVectorStore through optional WeaviateAsyncClient

[BobMerkus]

Asynchronous support for WeaviateVectorStore

This PR adds adds an optional WeaviateAsyncClient to WeaviateVectorStore.client_async in order to fully support the asynchronous methods implemented by the base VectorStore.
Closes: #207

Description

There is no proper support for the asynchronous methods on the WeaviateVectorStore, as mentioned in Async client support #207 . The VectorStore currently uses the run_in_executor langchain utility on all the synchronous methods of the WeaviateVectorStore, leading to a lot of resource warnings when used inside async context. This implementation should solve these issues and lead to overall efficiency improvements when used inside async context. The async tests run about 2x as fast compared to the original tests (48s vs. 23s for me), even though there are more of them.

I've attempted to implement this with backwards compatibility, so when no client_async is passed along the default client, the methods still call the synchronous methods in the same way the base vector store currently does. Overall the test coverage has been increased to 98.66% through mocking and error asserts.

Please let me know if any changes are required, there still seems to be some room for improvements regarding shared logic between the sync/async implementation. Another approach would be to support client: WeaviateClient | WeaviateAsyncClient and decide which implementation to use based on the type of client supplied. I took a brief look at this, but it requires a lot of refactoring of the current implementation. This approach will arguably result in cleaner and more efficient code as it avoids the need to pass a sync client along with the async client.

[BobMerkus]

@hsm207 Could you take a look at this?

[a1ekseev]

@BobMerkus There are conflicts that need to be resolved.

[hsm207]

Hey @BobMerkus,

Appreciate the contribution!

Just FYI, I’m not with Weaviate anymore so I have zero say on this integration these days. Honestly, I don’t even know who’s running the show or what the maintenance policy is for this integration now.

You’ll probably get a quicker answer if you ping the Weaviate community manager in the Weaviate Community Slack channel.

Good luck! 🚀

[BobMerkus]

@BobMerkus There are conflicts that need to be resolved.

Have rebased the branch, should be fixed now

[BobMerkus]

Hey @BobMerkus,

Appreciate the contribution!

Just FYI, I’m not with Weaviate anymore so I have zero say on this integration these days. Honestly, I don’t even know who’s running the show or what the maintenance policy is for this integration now.

You’ll probably get a quicker answer if you ping the Weaviate community manager in the Weaviate Community Slack channel.

Good luck! 🚀

Hi @hsm207,

Thanks for your response! No worries, this is not really a priority to me but it seems like a nice feature to support. Thanks for the suggestion, I'll check the Weaviate Community Slack channel.

Good luck to you as well 👾

[DhruvGorasiya]

@BobMerkus Thanks for the contribution! Could you please update your branch with the latest changes from main so that the checks can run and we can proceed with the review?

[BobMerkus]

@BobMerkus Thanks for the contribution! Could you please update your branch with the latest changes from main so that the checks can run and we can proceed with the review?

@DhruvGorasiya I have rebased the branch, should be ready for CI checks now. Please let me know if any changes are required.