History

Connor Brewster e7be342256 feat(tvix/store): concurrently upload small blobs during nar ingestion Currently all blobs are uploaded serially when ingesting NARs. If a NAR contains many, small blobs, ingestion may become slow if there is a lot of round-trip latency to the blob service. This makes the NAR ingester use the ConcurrentBlobUploader which allows for buffering small blobs in memory so they can be uploaded concurrently to the blob service without blocking further deserialization. Change-Id: I093a73770232df12d9a11e5d901b99c08505c3cb Reviewed-on: https://cl.tvl.fyi/c/depot/+/11694 Reviewed-by: flokli <flokli@flokli.de> Tested-by: BuildkiteCI		2024-05-20 15:21:51 +00:00
..
docs	chore(tvix/nar-bridge): move to nar-bridge-go	2024-05-15 21:31:36 +00:00
protos	refactor(tvix/*/protos): separate lint target	2023-12-11 22:35:39 +00:00
src	feat(tvix/store): concurrently upload small blobs during nar ingestion	2024-05-20 15:21:51 +00:00
build.rs	fix(tvix): don't emit rerun-if-changed	2024-03-16 09:34:10 +00:00
Cargo.toml	chore(tvix): drop json feature for tracing-subscriber	2024-05-16 21:05:51 +00:00
default.nix	test(tvix/[ca]store): enable bigtable only with "integration" feature	2024-05-03 08:53:09 +00:00
README.md	fix(tvix/store): rename Read method in Readme	2023-09-26 15:24:32 +00:00

README.md

//tvix/store

This contains the code hosting the tvix-store.

For the local store, Nix realizes files on the filesystem in /nix/store (and maintains some metadata in a SQLite database). For "remote stores", it communicates this metadata in NAR (Nix ARchive) and NARInfo format.

Compared to the Nix model, tvix-store stores data on a much more granular level than that, which provides more deduplication possibilities, and more granular copying.

However, enough information is preserved to still be able to render NAR and NARInfo when needed.

More Information

The store consists out of two different gRPC services, tvix.castore.v1 for the low-level content-addressed bits, and tvix.store.v1 for the Nix and StorePath-specific bits.

Check the protos/ subfolder both here and in castore for the definition of the exact RPC methods and messages.

Interacting with the GRPC service manually

The shell environment in //tvix provides evans, which is an interactive REPL-based gPRC client.

You can use it to connect to a tvix-store and call the various RPC methods.

$ cargo run -- daemon &
$ evans --host localhost --port 8000 -r repl
  ______
 |  ____|
 | |__    __   __   __ _   _ __    ___
 |  __|   \ \ / /  / _. | | '_ \  / __|
 | |____   \ V /  | (_| | | | | | \__ \
 |______|   \_/    \__,_| |_| |_| |___/

 more expressive universal gRPC client


localhost:8000> package tvix.castore.v1
tvix.castore.v1@localhost:8000> service BlobService

tvix.castore.v1.BlobService@localhost:8000> call Put --bytes-from-file
data (TYPE_BYTES) => /run/current-system/system
{
  "digest": "KOM3/IHEx7YfInAnlJpAElYezq0Sxn9fRz7xuClwNfA="
}

tvix.castore.v1.BlobService@localhost:8000> call Read --bytes-as-base64
digest (TYPE_BYTES) => KOM3/IHEx7YfInAnlJpAElYezq0Sxn9fRz7xuClwNfA=
{
  "data": "eDg2XzY0LWxpbnV4"
}

$ echo eDg2XzY0LWxpbnV4 | base64 -d
x86_64-linux

Thanks to tvix-store providing gRPC Server Reflection (with reflection feature), you don't need to point evans to the .proto files.