crashes

[avnerbarr]

Hi Getting crashes with this message:

thread '<unnamed>' panicked at 'Channel from calling thread disconnected: "SendError(..)"'

specifically:

                    let batch_output = handler(batch_input $(, &context.$ctx_arg )*);
                    for (output, mut result_tx) in batch_output.into_iter().zip(batch_txs) {
                        result_tx.send(output).expect("Channel from calling thread disconnected");
                    }

Seems if the client end disconnects / hangs etc. this will cause the server to crash (batched_fn channel)

[epwalsh]

Hey @avnerbarr, are you able to reproduce this consistently? If so, how? I'd like to try.

[avnerbarr]

Hi @epwalsh

The way I would suggest is to create a toy project (I ran in debug) which calls out to the server and kill the process before the server is able to respond.

Very trivial example I tried which seems to do the trick (most times):

async fn call_server(&self, text: &str) {

        let mut req = Request::from(text.to_string());
        
        let client = Self::builder();

        let p = client.json(&req);

        let a = p.timeout(std::time::Duration::from_secs(3)).send().await?;

        a.json::<Response>()
            .await
            .map_err(|error| {
                Self::report_error(&error);
                CloudError::from(error)
            })
}


fn builder() -> RequestBuilder {
        reqwest::Client::new().post(format!(
            "{}://{}:{}/generate",
            Self::protocol(),
            Self::host(),
            Self::port()
        )) // stubbed
    }

The server is per the code example, but perhaps tweak the batch size and batch time to allow easier debugging