When HTTP/2 is configured and a servlet/response makes a "response.flushBuffer()" (response is a ServletResponse object), sometimes it closes all channels of the connections.



In the source code of org.apache.coyote.AbstractProcessor.java, 'public final void action(ActionCode actionCode, Object param)' method, I can see "CLOSE" case:

---
        case CLOSE: {
            action(ActionCode.COMMIT, null);
            try {
                finishResponse();
            } catch (CloseNowException cne) {
                setErrorState(ErrorState.CLOSE_NOW, cne);
            } catch (IOException e) {
                setErrorState(ErrorState.CLOSE_CONNECTION_NOW, e);
            }
            break;
        }
---

It is easy to see that with "finishResponse()", if it throws an exception, it tries first to capture "CloseNowException".
If it is the case, then it "setErrorState(ErrorState.CLOSE_NOW, cne);"; so it close only the channel; not the whole connection.

But this behavior is not the same with "case CLIENT_FLUSH:".
If " flush();" throws an exception, it closes the whole connection with " setErrorState(ErrorState.CLOSE_CONNECTION_NOW, e);".

My suggestion is to try catch first 'CloseNowException' (as in CLOSE case); and if it is catched, then close only the channel, not the whole connection. So the code could be something like this:

-----

        case CLIENT_FLUSH: {
            action(ActionCode.COMMIT, null);
            try {
                flush();
            } catch (CloseNowException cne) {
                setErrorState(ErrorState.CLOSE_NOW, cne);
                 response.setErrorException(cne);  //I am not sure about this line
            } catch (IOException e) {
                setErrorState(ErrorState.CLOSE_CONNECTION_NOW, e);
                response.setErrorException(e);
            }
            break;
        }
-----
Then, if an error is producced, it lets other chnnels to completed.

I implemented it in my enviroment, and it works; but I do know know if it "breaks" some kind of standard or RFC or what else.