RST_STREAM sent by a Server Streaming client does not signal the gRPC layer

[mattp-swirldslabs]

Environment Details

• Helidon Version: 4.1.1
• Helidon SE
• JDK version: 21.0.4
• OS: Mac OS 14.6.1

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Problem Description

RST_STREAM sent by a Server Streaming client does not signal the gRPC layer

Steps to reproduce:

1. Start a Server Streaming connection to Helidon using a client like Postman and confirm you're receiving streaming data from the server.
2. Place a breakpoint in the Http2ServerStream.rstStream() method
3. Use the Postman cancel button to send a rst_stream to terminate the connection
4. The state changes to CLOSED but the Http2StreamWriter (passed here:

   helidon/webserver/http2/src/main/java/io/helidon/webserver/http2/spi/Http2SubProtocolSelector.java

   Line 60 in 51b942a

   Http2StreamWriter streamWriter,

   ) continues to accept data from the gRPC layer.
5. Our application above the gRPC layer needs an exception or some signal from Helidon to know that it needs to stop streaming data.

• The "TODO" comment in the Http2ServerStream.rstStream() method seems to indicate this might be a known issue