How to increase the max frame size?

[zhengyi-yang]

I have encountered the error of ClientHandler errored out: frame size too big, how can I increase the max frame size in tarpc?

[tikue]

Hi! Which transport/serialization protocol are you using?

[zhengyi-yang]

I'm using bincode

[henrycg]

+1 on this question. It would be great to have some example code showing how to increase the frame size (whether for JSON or bincode).

[tikue]

Sorry for another clarification -- is this via tokio-serde? The reason I ask is because it may be a question for them. I suspect that tokio-serde's bincode codec doesn't currently support modifying the frame size.

[henrycg]

Yes, I am just following the example code here. It looks like there is probably a way to make this work by somehow calling this function. Increasing the max frame size may not be strictly a tarpc problem/issue, but if it's easy to do, it would be great to have some example code documenting how.

If I figure out a clean way to increase the maximum frame size, I can submit a PR. If you know of a simple way to do it, that would be great too.

[tikue]

I'll do a bit of investigation, but my hope is to do it via tokio-serde -- if you get to it before me, I'd be very thankful for a PR with an example of how to do this!

[awaited-hare]

Also encountered this. Has anyone figured out something?

[tikue]

It will be possible to do this via tokio-serde once carllerche/tokio-serde#17 is merged. It would look something like this:

tarpc::serde_transport::tcp::listen(addr, || {
    tokio_serde::Bincode::from(
        // Configure your preferred frame size here.
        bincode::options()
            // 2^32 bytes
            .with_limit(4294967296)
    )
})

Edit: I pushed a branch with an example of this. If you want to try it yourself. you'll need to modify your Cargo.toml to point to my branch of tokio-serde.

[awaited-hare]

It will be possible to do this via tokio-serde once carllerche/tokio-serde#17 is merged. It would look something like this:

tarpc::serde_transport::tcp::listen(addr, || {
    tokio_serde::Bincode::from(
        // Configure your preferred frame size here.
        bincode::options()
            // 2^32 bytes
            .with_limit(4294967296)
    )
})

Edit: I pushed a branch with an example of this. If you want to try it yourself. you'll need to modify your Cargo.toml to point to my branch of tokio-serde.

Thanks! After overriding tokio-serde dependency to your git repo, I still get a bunch of ClientHandler errored out: frame size too big (always printed on the server side). Any possible reason?

Client:

    let transport = tarpc::serde_transport::tcp::connect(
        server_addr
            .parse::<std::net::SocketAddr>()
            .unwrap_or_else(|_| {
                panic!("cannot parse server_addr {:?}", server_addr);
            }),
        tokio_serde::formats::Bincode::from(bincode::options().with_no_limit()),
    )
    .await
    .unwrap();

    let client = MyServiceClient::new(tarpc::client::Config::default(), transport)
        .spawn()
        .unwrap();

Server:

    tarpc::serde_transport::tcp::listen(
        (std::net::IpAddr::from([0, 0, 0, 0]), config.server_port),
        || tokio_serde::formats::Bincode::from(bincode::options().with_no_limit()),
    )
    .await?
    .filter_map(|r| futures::future::ready(r.ok()))
    .map(tarpc::server::BaseChannel::with_defaults)
    .map(|channel| {
        let server = MyServer {
            socket_addr: channel.as_ref().peer_addr().unwrap(),
        };
        channel.respond_with(server.serve()).execute()
    })
    .buffer_unordered(20)
    .for_each(|_| async {})
    .await;

[awaited-hare]

@tikue It seems that bincode's default byte limit is Infinite, so the error may not come from bincode?

[tikue]

Ah! You're totally right. I think it's coming from the hard-coded LengthDelimitedCodec in tarpc::serde_framed::Transport. I'm sorry about that! It shouldn't be too hard to add another method that allows configuring the length-delimited codec.

[awaited-hare]

Ah! You're totally right. I think it's coming from the hard-coded LengthDelimitedCodec in tarpc::serde_framed::Transport. I'm sorry about that! It shouldn't be too hard to add another method that allows configuring the length-delimited codec.

Thanks :) It seems to be this line: https://github.com/google/tarpc/blob/v0.21.1/tarpc/src/serde_transport/mod.rs#L102.

Not sure about where to appropriately add the method though.

[tikue]

I pushed a commit to master that exposes the framing config options. I updated the example service to show how to do this. Let me know if it fixes it :)

[awaited-hare]

I'm still getting ClientHandler errored out: frame size too big. Trying to construct a simple example.

[tikue]

As far as I can tell, it's working for me locally. I can set the frame size very small and force the client requests to error, and when I set the frame size bigger, the errors stop.

[awaited-hare]

As far as I can tell, it's working for me locally. I can set the frame size very small and force the client requests to error, and when I set the frame size bigger, the errors stop.

Turns out it works fines. I was still getting frame size too big because there's an HTTP client querying the same port (and tarpc doesn't know it is an HTTP client, and still interpret the first 4 bytes as the frame lengths, which could be very large).

Thanks a lot for your help! @tikue

[tikue]

Very glad to hear it's working! I'll publish a version later today.

[tikue]

I just published v0.22.0 which incorporates this change.