Streaming example from readme deadlocks if seq instance is restarted

[akilin]

Seq event streaming from readme deadlocks when disposing the stream when the seq instance is restarted.

I am attempting to stream seq events for additional processing. I was testing how it handles the scenario where the seq instance is restarted, and it appears to deadlock when disposing of the stream.

var seqUrl = "http://localhost:5341";

Log.Logger = new LoggerConfiguration()
    .WriteTo.Seq(seqUrl)
    .WriteTo.Console()
    .CreateLogger();

var filter = "@Level = 'Error'";

var connection = new SeqConnection(seqUrl);

while (true)
{
    await connection.EnsureConnectedAsync(TimeSpan.FromSeconds(15));
    
    var stream = await connection.Events.StreamAsync<JObject>(filter: filter);

    var subscription = stream.Subscribe(
        log => Log.Information("OnNext"),
        ex => Log.Information("OnError"),
        () => Log.Information("OnCompleted")
    );

    await Task.Delay(1000);
    Log.Error("logging fake error to test seq streaming");

    await stream;

    subscription.Dispose();
    stream.Dispose(); // <-- stuck here

    Log.Information("loop end");
}

It seems to get stuck while waiting for _run task to finish here:

seq-api/src/Seq.Api/Streams/ObservableStream.cs

Line 220 in 4c650b2

_run.ConfigureAwait(false).GetAwaiter().GetResult();

Repo with reproduction: https://github.com/akilin/demos/tree/master/seq-stream

Steps to reproduce:

• clone the linked repo
• navigate to seq-stream folder
• docker-compose up
• run the dotnet app and wait until you see OnNext in the console logs
• docker-compose restart (to restart seq and close the stream)
• app deadlocks when disposing the stream

[KodrAus]

Thanks for the report @akilin. If you're attempting to hang-up from the client-side of the stream we shouldn't block. Since the websocket is closed by the server on restart I would've expected it to throw, but we'll investigate and see what's going on there.