io.netty.handler.codec.http2.Http2Exception: Request stream nnnn is not correct for server connection

[en-vee]

Hi,
I have an HTTP/2 webserver using Netty and I have noticed that at high number of requests especially more than around 2500 requests per second (RPS), I see the following in my error logs (stream ID is just an example).
Any reason what could be causing this exception ? Also, this error message is received on the client side on a different Stream Id.

io.netty.handler.codec.http2.Http2Exception: Request stream 72835 is not correct for server connection
	at io.netty.handler.codec.http2.Http2Exception.connectionError(Http2Exception.java:108) ~[http2-gateway-uber.jar:5232.01]
	at io.netty.handler.codec.http2.DefaultHttp2Connection$DefaultEndpoint.checkNewStreamAllowed(DefaultHttp2Connection.java:885) ~[http2-gateway-uber.jar:5232.01]
	at io.netty.handler.codec.http2.DefaultHttp2Connection$DefaultEndpoint.createStream(DefaultHttp2Connection.java:751) ~[http2-gateway-uber.jar:5232.01]
	at io.netty.handler.codec.http2.DefaultHttp2Connection$DefaultEndpoint.createStream(DefaultHttp2Connection.java:671) ~[http2-gateway-uber.jar:5232.01]
	at io.netty.handler.codec.http2.DefaultHttp2ConnectionEncoder.writeHeaders0(DefaultHttp2ConnectionEncoder.java:201) ~[http2-gateway-uber.jar:5232.01]
	at io.netty.handler.codec.http2.DefaultHttp2ConnectionEncoder.writeHeaders(DefaultHttp2ConnectionEncoder.java:167) ~[http2-gateway-uber.jar:5232.01]
	at io.netty.handler.codec.http2.DecoratingHttp2FrameWriter.writeHeaders(DecoratingHttp2FrameWriter.java:53) ~[http2-gateway-uber.jar:5232.01]
	at io.vertx.core.http.impl.VertxHttp2ConnectionHandler.writeHeaders(VertxHttp2ConnectionHandler.java:196) ~[http2-gateway-uber.jar:5232.01]
	at io.vertx.core.http.impl.VertxHttp2Stream.doWriteHeaders(VertxHttp2Stream.java:188) ~[http2-gateway-uber.jar:5232.01]
	at io.vertx.core.http.impl.Http2ServerStream.doWriteHeaders(Http2ServerStream.java:117) ~[http2-gateway-uber.jar:5232.01]
	at io.vertx.core.http.impl.VertxHttp2Stream.writeHeaders(VertxHttp2Stream.java:180) ~[http2-gateway-uber.jar:5232.01]
	at io.vertx.core.http.impl.Http2ServerResponse.checkSendHeaders(Http2ServerResponse.java:487) ~[http2-gateway-uber.jar:5232.01]
	at io.vertx.core.http.impl.Http2ServerResponse.write(Http2ServerResponse.java:453) ~[http2-gateway-uber.jar:5232.01]
	at io.vertx.core.http.impl.Http2ServerResponse.end(Http2ServerResponse.java:395) ~[http2-gateway-uber.jar:5232.01]
	at io.vertx.core.http.impl.Http2ServerResponse.end(Http2ServerResponse.java:374) ~[http2-gateway-uber.jar:5232.01]