Bug: There was a problem with a datastore transaction: PessimisticLock error: ResolveLockError about surrealdb

[tobiemh]

Hi @rushmorem you've actually found 2 bugs here! One in SurrealDB and one in TiKV (or probably the TiKV client).

In SurrealDB we are using pessimistic transactions when we should be using optimistic transactions 😖! This is a logic error (albeit one that shouldn't result in any failure).

In TiKV, there is an issue with pessimistic transactions resulting in locks not being removed from the key-value store, even though the transaction has finished successfully. This does not happen when the application is run for the first time, but only after the application is stopped and restarted. I have submitted an issue for this: tikv/client-rust#366

To solve this I'll be ensuring that we are using optimistic transactions, which does not have this same issue, and hopefully the underlying error can be solved in due course anyway!

[tobiemh]

Thanks for this @rushmorem 👍 - will look into this...

[rushmorem]

Hi @tobiemh. Awesome! Thank you so much!

[Jayuda]

How to try this update. I Have this problems too.
Thanks

[rushmorem]

@Jayuda Building from source with the kv-tikv feature is a bit tricky right now. Do you have a flake-enabled nix (https://nixos.org/download.html)? I could share my Nix flake.

[Jayuda]

Sorry i am not familiar with nix - but i will find out how to use it. Can you give me nix flake - so i will try build it. Thanks verry much @rushmorem

[rushmorem]

@Jayuda I'm working on integrating Nix flakes into this repo at #100. If you are on Linux and have a flake-enabled Nix package manager, it should already work for you. I'm still to add tests for it in the CI to check other platforms.

If you just want to compile and install the binary, you can do:-

nix profile install github:rushmorem/surrealdb/feature-97-nix-flake

which downloads the source from my WIP branch, compiles and installs the binary to your PATH.

If you just want cargo to work with this repo so you can play with it, clone this repo, switch to it and then just run:-

nix develop github:rushmorem/surrealdb/feature-97-nix-flake

This spawns a shell with all the dependencies of this project installed. This allows you to run cargo build, cargo check etc.