Effective Implementation of WebSocket Closing Handshake Between C# Clients and Node.js Servers

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The Problem

Key Questions

How can you detect that the connection is in the CLOSING state on the server?

What functions from the ws library will allow you to send an acknowledgment back to the C# client to update its state to Closed?

The Solution

After thorough investigation, a solution has been discovered. Here's how to handle the closing handshake effectively:

When the C# Client Initiates the Close

Switch from CloseOutputAsync to CloseAsync:

The key change is that the C# client should call CloseAsync instead of CloseOutputAsync. This allows the server to properly recognize the close request and transition its state accordingly.

Once the server receives the close request through CloseAsync, it will transition its state to CLOSED without going through the CLOSING state. This immediate closure will ensure that the C# client updates its state to Closed, resolving the state inconsistency.

In this scenario, the C# client should still utilize CloseOutputAsync to properly respond to the server's close request.

State Transition on the C# Client:

Open - CloseReceived - CloseSent - Closed.

This will ensure that the client responds correctly and acknowledges the closure.

Conclusion

Implement these changes in your WebSocket interactions to ensure smooth and efficient details management in your networking applications. If you have further questions or need assistance with WebSocket implementations, feel free to reach out!