vertx-http-proxy gets stuck when the original client is unavailable with a pending request.

[edu-gimenez]

I am using vertx-http-proxy:4.5.13 in a Vert.x server, and sometimes the server becomes unresponsive. I have realized that when the original client dies while there are pending requests in progress, the HTTP client responsible for the proxy gets stuck.

I believe the issue comes from the interaction between ProxiedRequest and PipeImpl, but I am not 100% sure.
These are the exceptions that I get before the client gets stuck.

2025-03-28 08:08:28.939 [vert.x-eventloop-thread-2] INFO  ProxyServer.lambda$start$3:48 - ProxyVerticle deployed successfully
2025-03-28 08:08:58.360 [vert.x-eventloop-thread-0] TRACE HttpServerImpl.: - Connection failure
io.netty.channel.StacklessClosedChannelException: null
        at io.netty.channel.AbstractChannel$AbstractUnsafe.write(Object, ChannelPromise)(Unknown Source) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
2025-03-28 08:08:58.370 [vert.x-eventloop-thread-0] TRACE ReverseProxy.: - Error in sending the response
java.lang.IllegalArgumentException: Stream no longer exists: 403
        at io.netty.handler.codec.http2.DefaultHttp2ConnectionEncoder.requireStream(DefaultHttp2ConnectionEncoder.java:418) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.DefaultHttp2ConnectionEncoder.writeData(DefaultHttp2ConnectionEncoder.java:124) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.DecoratingHttp2FrameWriter.writeData(DecoratingHttp2FrameWriter.java:37) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.VertxHttp2ConnectionHandler.writeData(VertxHttp2ConnectionHandler.java:233) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.VertxHttp2Stream.doWriteData(VertxHttp2Stream.java:267) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.VertxHttp2Stream.writeData(VertxHttp2Stream.java:236) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.Http2ServerResponse.write(Http2ServerResponse.java:469) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.Http2ServerResponse.write(Http2ServerResponse.java:354) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.Http2ServerResponse.write(Http2ServerResponse.java:48) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.streams.impl.PipeImpl.lambda$to$1(PipeImpl.java:81) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.impl.ContextInternal.dispatch(ContextInternal.java:270) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.HttpEventHandler.handleChunk(HttpEventHandler.java:51) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.HttpClientResponseImpl.handleChunk(HttpClientResponseImpl.java:239) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.Http2ClientConnection$StreamImpl.handleData(Http2ClientConnection.java:501) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.VertxHttp2Stream.lambda$new$1(VertxHttp2Stream.java:76) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.streams.impl.InboundBuffer.handleEvent(InboundBuffer.java:279) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.streams.impl.InboundBuffer.write(InboundBuffer.java:157) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.impl.ContextImpl.execute(ContextImpl.java:327) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.impl.DuplicatedContext.execute(DuplicatedContext.java:158) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.VertxHttp2Stream.onData(VertxHttp2Stream.java:123) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.Http2ConnectionBase.onDataRead(Http2ConnectionBase.java:316) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.Http2FrameListenerDecorator.onDataRead(Http2FrameListenerDecorator.java:34) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.Http2FrameListenerDecorator.onDataRead(Http2FrameListenerDecorator.java:34) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.Http2EmptyDataFrameListener.onDataRead(Http2EmptyDataFrameListener.java:49) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.DefaultHttp2ConnectionDecoder$FrameReadListener.onDataRead(DefaultHttp2ConnectionDecoder.java:320) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.DefaultHttp2FrameReader.readDataFrame(DefaultHttp2FrameReader.java:409) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.DefaultHttp2FrameReader.processPayloadState(DefaultHttp2FrameReader.java:244) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.DefaultHttp2FrameReader.readFrame(DefaultHttp2FrameReader.java:164) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.DefaultHttp2ConnectionDecoder.decodeFrame(DefaultHttp2ConnectionDecoder.java:186) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.DecoratingHttp2ConnectionDecoder.decodeFrame(DecoratingHttp2ConnectionDecoder.java:61) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.DecoratingHttp2ConnectionDecoder.decodeFrame(DecoratingHttp2ConnectionDecoder.java:61) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.Http2ConnectionHandler$FrameDecoder.decode(Http2ConnectionHandler.java:391) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.Http2ConnectionHandler.decode(Http2ConnectionHandler.java:451) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:530) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:469) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:290) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.VertxHttp2ConnectionHandler.channelRead(VertxHttp2ConnectionHandler.java:405) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:444) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.timeout.IdleStateHandler.channelRead(IdleStateHandler.java:289) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:442) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1357) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:440) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:868) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:166) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:796) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:732) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:658) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:562) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:998) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at java.lang.Thread.run(Thread.java:1583) [?:?]
2025-03-28 08:08:58.373 [vert.x-eventloop-thread-0] TRACE ReverseProxy.: - Error in sending the request
java.lang.IllegalStateException: Request has already been read
        at io.vertx.core.http.impl.Http2ServerRequest.checkEnded(Http2ServerRequest.java:205) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.Http2ServerRequest.pause(Http2ServerRequest.java:257) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.Http2ServerRequest.pause(Http2ServerRequest.java:48) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.streams.ReadStream.pipe(ReadStream.java:114) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.httpproxy.impl.ProxiedRequest.sendRequest(ProxiedRequest.java:209) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.httpproxy.impl.ProxiedRequest.send(ProxiedRequest.java:242) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.impl.future.Composition.onSuccess(Composition.java:38) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.impl.future.FutureBase.emitSuccess(FutureBase.java:66) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.impl.future.FutureImpl.tryComplete(FutureImpl.java:259) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.impl.future.Composition$1.onSuccess(Composition.java:62) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.impl.future.FutureBase.emitSuccess(FutureBase.java:66) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.impl.future.FutureImpl.tryComplete(FutureImpl.java:259) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.HttpClientImpl.lambda$doRequest$3(HttpClientImpl.java:392) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.impl.ContextImpl.emit(ContextImpl.java:342) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.impl.DuplicatedContext.emit(DuplicatedContext.java:163) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.Http2ClientConnection.createStream(Http2ClientConnection.java:157) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.HttpClientImpl.lambda$doRequest$4(HttpClientImpl.java:372) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.net.impl.pool.Endpoint.lambda$getConnection$0(Endpoint.java:52) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.SharedClientHttpStreamEndpoint$Request.handle(SharedClientHttpStreamEndpoint.java:162) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.SharedClientHttpStreamEndpoint$Request.handle(SharedClientHttpStreamEndpoint.java:123) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.impl.ContextImpl.emit(ContextImpl.java:342) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.impl.ContextImpl.emit(ContextImpl.java:335) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.net.impl.pool.SimpleConnectionPool$LeaseImpl.emit(SimpleConnectionPool.java:714) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.net.impl.pool.SimpleConnectionPool$Recycle$1.run(SimpleConnectionPool.java:735) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.net.impl.pool.Task.runNextTasks(Task.java:43) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.net.impl.pool.CombinerExecutor.submit(CombinerExecutor.java:91) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.net.impl.pool.SimpleConnectionPool.execute(SimpleConnectionPool.java:244) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.net.impl.pool.SimpleConnectionPool.recycle(SimpleConnectionPool.java:751) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.net.impl.pool.SimpleConnectionPool.access$3300(SimpleConnectionPool.java:79) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.net.impl.pool.SimpleConnectionPool$LeaseImpl.recycle(SimpleConnectionPool.java:710) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.HttpClientImpl.lambda$doRequest$2(HttpClientImpl.java:376) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.Http2ClientConnection$Stream.onClose(Http2ClientConnection.java:393) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.Http2ConnectionBase.onStreamClosed(Http2ConnectionBase.java:157) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.VertxHttp2ConnectionHandler$1.onStreamClosed(VertxHttp2ConnectionHandler.java:93) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.DefaultHttp2Connection.notifyClosed(DefaultHttp2Connection.java:355) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.DefaultHttp2Connection$ActiveStreams.removeFromActiveStreams(DefaultHttp2Connection.java:1034) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.DefaultHttp2Connection$ActiveStreams.deactivate(DefaultHttp2Connection.java:990) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.DefaultHttp2Connection$DefaultStream.close(DefaultHttp2Connection.java:515) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.DefaultHttp2Connection$DefaultStream.close(DefaultHttp2Connection.java:521) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.Http2ConnectionHandler.doCloseStream(Http2ConnectionHandler.java:919) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.Http2ConnectionHandler.closeStream(Http2ConnectionHandler.java:627) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.Http2ConnectionHandler.closeStreamRemote(Http2ConnectionHandler.java:619) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.DefaultHttp2ConnectionDecoder$FrameReadListener.onDataRead(DefaultHttp2ConnectionDecoder.java:323) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.DefaultHttp2FrameReader.readDataFrame(DefaultHttp2FrameReader.java:409) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.DefaultHttp2FrameReader.processPayloadState(DefaultHttp2FrameReader.java:244) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.DefaultHttp2FrameReader.readFrame(DefaultHttp2FrameReader.java:164) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.DefaultHttp2ConnectionDecoder.decodeFrame(DefaultHttp2ConnectionDecoder.java:186) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.DecoratingHttp2ConnectionDecoder.decodeFrame(DecoratingHttp2ConnectionDecoder.java:61) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.DecoratingHttp2ConnectionDecoder.decodeFrame(DecoratingHttp2ConnectionDecoder.java:61) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.Http2ConnectionHandler$FrameDecoder.decode(Http2ConnectionHandler.java:391) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.Http2ConnectionHandler.decode(Http2ConnectionHandler.java:451) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:530) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:469) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:290) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.VertxHttp2ConnectionHandler.channelRead(VertxHttp2ConnectionHandler.java:405) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:444) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.timeout.IdleStateHandler.channelRead(IdleStateHandler.java:289) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:442) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1357) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:440) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:868) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:166) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:796) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:732) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:658) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:562) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:998) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at java.lang.Thread.run(Thread.java:1583) [?:?]
2025-03-28 08:08:58.374 [vert.x-eventloop-thread-0] TRACE ReverseProxy.: - Error in sending the response
java.lang.IllegalStateException: Request has already been read
        at io.vertx.core.http.impl.Http2ServerRequest.checkEnded(Http2ServerRequest.java:205) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.Http2ServerRequest.fetch(Http2ServerRequest.java:271) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.Http2ServerRequest.resume(Http2ServerRequest.java:265) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.Http2ServerRequest.resume(Http2ServerRequest.java:48) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.httpproxy.impl.ProxiedRequest.release(ProxiedRequest.java:154) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.httpproxy.impl.ReverseProxy.lambda$handle$1(ReverseProxy.java:81) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.impl.future.Composition.onFailure(Composition.java:50) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.impl.future.FutureBase.emitFailure(FutureBase.java:81) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.impl.future.FutureImpl.tryFail(FutureImpl.java:278) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.impl.future.Composition.onSuccess(Composition.java:40) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.impl.future.FutureBase.emitSuccess(FutureBase.java:66) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.impl.future.FutureImpl.tryComplete(FutureImpl.java:259) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.impl.future.Composition$1.onSuccess(Composition.java:62) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.impl.future.FutureBase.emitSuccess(FutureBase.java:66) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.impl.future.FutureImpl.tryComplete(FutureImpl.java:259) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.HttpClientImpl.lambda$doRequest$3(HttpClientImpl.java:392) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.impl.ContextImpl.emit(ContextImpl.java:342) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.impl.DuplicatedContext.emit(DuplicatedContext.java:163) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.Http2ClientConnection.createStream(Http2ClientConnection.java:157) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.HttpClientImpl.lambda$doRequest$4(HttpClientImpl.java:372) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.net.impl.pool.Endpoint.lambda$getConnection$0(Endpoint.java:52) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.SharedClientHttpStreamEndpoint$Request.handle(SharedClientHttpStreamEndpoint.java:162) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.SharedClientHttpStreamEndpoint$Request.handle(SharedClientHttpStreamEndpoint.java:123) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.impl.ContextImpl.emit(ContextImpl.java:342) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.impl.ContextImpl.emit(ContextImpl.java:335) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.net.impl.pool.SimpleConnectionPool$LeaseImpl.emit(SimpleConnectionPool.java:714) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.net.impl.pool.SimpleConnectionPool$Recycle$1.run(SimpleConnectionPool.java:735) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.net.impl.pool.Task.runNextTasks(Task.java:43) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.net.impl.pool.CombinerExecutor.submit(CombinerExecutor.java:91) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.net.impl.pool.SimpleConnectionPool.execute(SimpleConnectionPool.java:244) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.net.impl.pool.SimpleConnectionPool.recycle(SimpleConnectionPool.java:751) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.net.impl.pool.SimpleConnectionPool.access$3300(SimpleConnectionPool.java:79) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.net.impl.pool.SimpleConnectionPool$LeaseImpl.recycle(SimpleConnectionPool.java:710) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.HttpClientImpl.lambda$doRequest$2(HttpClientImpl.java:376) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.Http2ClientConnection$Stream.onClose(Http2ClientConnection.java:393) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.Http2ConnectionBase.onStreamClosed(Http2ConnectionBase.java:157) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.VertxHttp2ConnectionHandler$1.onStreamClosed(VertxHttp2ConnectionHandler.java:93) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.DefaultHttp2Connection.notifyClosed(DefaultHttp2Connection.java:355) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.DefaultHttp2Connection$ActiveStreams.removeFromActiveStreams(DefaultHttp2Connection.java:1034) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.DefaultHttp2Connection$ActiveStreams.deactivate(DefaultHttp2Connection.java:990) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.DefaultHttp2Connection$DefaultStream.close(DefaultHttp2Connection.java:515) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.DefaultHttp2Connection$DefaultStream.close(DefaultHttp2Connection.java:521) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.Http2ConnectionHandler.doCloseStream(Http2ConnectionHandler.java:919) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.Http2ConnectionHandler.closeStream(Http2ConnectionHandler.java:627) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.Http2ConnectionHandler.closeStreamRemote(Http2ConnectionHandler.java:619) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.DefaultHttp2ConnectionDecoder$FrameReadListener.onDataRead(DefaultHttp2ConnectionDecoder.java:323) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.DefaultHttp2FrameReader.readDataFrame(DefaultHttp2FrameReader.java:409) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.DefaultHttp2FrameReader.processPayloadState(DefaultHttp2FrameReader.java:244) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.DefaultHttp2FrameReader.readFrame(DefaultHttp2FrameReader.java:164) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.DefaultHttp2ConnectionDecoder.decodeFrame(DefaultHttp2ConnectionDecoder.java:186) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.DecoratingHttp2ConnectionDecoder.decodeFrame(DecoratingHttp2ConnectionDecoder.java:61) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.DecoratingHttp2ConnectionDecoder.decodeFrame(DecoratingHttp2ConnectionDecoder.java:61) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.Http2ConnectionHandler$FrameDecoder.decode(Http2ConnectionHandler.java:391) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.http2.Http2ConnectionHandler.decode(Http2ConnectionHandler.java:451) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:530) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:469) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:290) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.VertxHttp2ConnectionHandler.channelRead(VertxHttp2ConnectionHandler.java:405) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:444) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.handler.timeout.IdleStateHandler.channelRead(IdleStateHandler.java:289) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:442) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1357) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:440) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:868) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:166) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:796) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:732) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:658) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:562) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:998) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at java.lang.Thread.run(Thread.java:1583) [?:?]

Do you have a reproducer?

I have created a small project to reproduce this error.
The project contains 3 main classes:

• Client with a jetty client (without vertx) that generates traffic, configurable with several options. This client terminates before receiving all responses
• BackendServer with a vertx server that receives the proxied requests
• ProxyServer, with a vertx server and client that proxies the requests. The client has been configured with Http2MaxSize and Http2MultiplexingLimit set to 1, to be able to reproduce the error as quickly as possible.

http-proxy-vertx-issue.zip

Steps to reproduce

1. Compile the fat-jar -> mvn package
2. Run the backend server -> java -cp target/http-proxy-vertx-issue-1.0-SNAPSHOT.jar com.http.proxy.vertx.issue.backend.BackendServer
3. Run the proxy server -> java -cp target/http-proxy-vertx-issue-1.0-SNAPSHOT.jar com.http.proxy.vertx.issue.proxy.ProxyServer
4. Run the client -> java -cp target/http-proxy-vertx-issue-1.0-SNAPSHOT.jar com.http.proxy.vertx.issue.client.App 2 200 0 100 0 0 GET http://localhost:20000/some/path 0 none (Client can be configured, use java -cp target/http-proxy-vertx-issue-1.0-SNAPSHOT.jar com.http.proxy.vertx.issue.client.App --help` to see all options)
5. Run the client again. The ProxyServer will no longer accept requests. (Since this appears to be a race condition, it may be necessary to run the client multiple times.)

[tsegismont]

Thank you for reporting, I'll look into it

[tsegismont]

@edu-gimenez this should be fixed with #118

Any chance for you to try a snapshot build with the fix?

[edu-gimenez]

Hi @tsegismont, it seems that the issue is resolved with #118.
I still think there are some strange behaviors, but I need more time to analyze them.
For now, this ticket can be closed.
Thanks!

[tsegismont]

Great, thanks for the update. Please go ahead and file new issues if required.

[edu-gimenez]

Hi @tsegismont ,
I'm sorry, but I have not been able to spend time on this topic.
I'm afraid the issue is still present in 4.5.14-SNAPSHOT. Could you please test it using the project I shared earlier, just by changing the vertx-http-proxy version?

That said, I believe there’s more than one issue here. While I think there are some unhandled corner cases in ReverseProxy, I also suspect there’s a different corner case in vertx-core.

In particular, there's a scenario where the HttpClientRequest is created, but the Http2ClientConnection stream is never initialized (for example, when the HttpServerRequest is reset when it is going to be piped).

2025-04-11 11:39:21.096 [vert.x-eventloop-thread-0] TRACE ReverseProxy.: - Error in sending the request
java.lang.IllegalStateException: Request has already been read
        at io.vertx.core.http.impl.Http2ServerRequest.checkEnded(Http2ServerRequest.java:206) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.Http2ServerRequest.pause(Http2ServerRequest.java:277) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.http.impl.Http2ServerRequest.pause(Http2ServerRequest.java:49) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]
        at io.vertx.core.streams.ReadStream.pipe(ReadStream.java:114) ~[http-proxy-vertx-issue-1.0-SNAPSHOT.jar:?]

In this case, the handler in HttpClientImpl#doRequest is never invoked:

stream.closeHandler(v -> {
    lease.recycle();
});

I guess that if the recycle method is not called, the slot is not released and the connection becomes blocked.

[tsegismont]

No problem to reopen, I thought it was fixed as per you previous comment. I'll take a look at the reproducer using the latest 4.5 version