Bug: Active Streams Silently Killed after connectionTimeout

[lapumb]

Any active stream(s) are silently killed without notifying the listeners once the first gRPC call is made after the ClientChannel's connectionTimeout is reached.

This feels like a bug to me.

gRPC Package Version Info:

  grpc:
    dependency: "direct main"
    description:
      name: grpc
      sha256: "5b99b7a420937d4361ece68b798c9af8e04b5bc128a7859f2a4be87427694813"
      url: "https://pub.dev"
    source: hosted
    version: "4.0.1"

Platform: Linux

Repro steps

1. Listen to a server --> client stream
2. Wait the ChannelOptions.connectionTimeout amount of time
3. Make a new / different gRPC call
4. The server detects the previously-active stream as 'cancelled'
5. The client continues to listen to the previously-active stream and never gets notified of cancellation (onDone)

Run the examples in https://github.com/lapumb/grpc-stream-example to easily reproduce.

Expected result: If the server detects a stream cancellation, the client (listener) should be notified via a stream error or the onDone event.

Actual result: The server ends the stream and the client continues to listen indefinitely.

Details

It appears that streams active when the connection timeout occurs will stay in a working / data receiving state until a new gRPC call is made after the connection timeout.

To get around this, I have had to implement heartbeats in my streams so my client can detect if it actually stopped receiving data altogether.

[BenJacques]

I'm experiencing this issue as well. It's causing enough of a headache that I'm considering ripping out streams altogether from my app and hosting a client and both ends of the connection for bi-directional communication.

[chazh]

I spent sometime looking into this based on the code provided and noticed that the stream actually does not report back any information about the connection being lost or disconnected.

I added to the a onConnectionStateChanged listener to the clientChannel that just prints out the state. This is what was reported in the logs.

Client Connection state changed: ConnectionState.connecting
Client Connection state changed: ConnectionState.ready
Received message: 0 at 2024-12-13 16:35:23.335838
--------------------------------------------------------------------------------
It has been 0:00:30.000000, the connection timeout should have taken effect!
Try pinging the server (by typing 's') to see if the connection is still active.
--------------------------------------------------------------------------------
Sending ping...
Client Connection state changed: ConnectionState.idle
Client Connection state changed: ConnectionState.connecting
Client Connection state changed: ConnectionState.ready
No messages received in the last 2 minutes
No messages received in the last 2 minutes

I would have expected the connection state to change to a disconnecting state or failure state at this point.

[lapumb]

Maybe a better way to phrase my problem: is this a limitation of gRPC? Or is this a bug in this package? I am very curious if other languages implement this in the same manner.