[HTTPCLIENT-2122] Details of H2ConnectionException are omitted by ConnectionClosedException

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 5.0.3
• Fix Version/s: 5.0.4, 5.1-beta1
• Component/s: HttpClient (async)
• Labels: http2 proxy
• Assignee: Unassigned
• Reporter: synth3
• Created: 19/Oct/20 21:50
• Updated: 22/Oct/20 18:28
• Resolved: 22/Oct/20 15:44

Description

As said in a comment of ticket HTTPCLIENT-2120 following a description of the error handling issue:

When I unbiasedly tried to establish a HTTP/2 connection via HTTP-Proxy I noticed that in the logs there is a frame size error that is not obvious from the exception thrown by Future<SimpleHttpResponse>.get():

• In the logs I can see Code FRAME_SIZE_ERROR and Frame size exceeds maximum which might be caused by trying to consume the HTTP-1.1 proxy response as HTTP/2
  • The associated Exception (H2ConnectionException: Frame size exceeds maximum) is omitted in org.apache.hc.core5.http2.impl.nio.AbstractH2StreamMultiplexer.onException(Exception) where ((ExecutableCommand) command).failed(new ConnectionClosedException()) is called

The following snipped can be used to reproduce the issue (coconutpi:8080 points to a basic squid 4.6 setup on a raspberry pi in my home network):

CloseableHttpAsyncClient client = HttpAsyncClients.custom().setVersionPolicy(HttpVersionPolicy.FORCE_HTTP_2)
        .setProxy(HttpHost.create("coconutpi:8080")).build();
client.start();
// throws org.apache.hc.core5.http.ConnectionClosedException: Connection is closed
client.execute(SimpleHttpRequests.get("https://http2.pro/client"), null).get();

StackTrace of exception thrown by Future<SimpleHttpResponse>.get():

ava.util.concurrent.ExecutionException: org.apache.hc.core5.http.ConnectionClosedException: Connection is closed
	at org.apache.hc.core5.concurrent.BasicFuture.getResult(BasicFuture.java:72)
	at org.apache.hc.core5.concurrent.BasicFuture.get(BasicFuture.java:85)
	at com.test.MinimalProxyTest.basicTest(MinimalProxyTest.java:40)
	at com.test.MinimalProxyTest.main(MinimalProxyTest.java:26)
Caused by: org.apache.hc.core5.http.ConnectionClosedException: Connection is closed
	at org.apache.hc.core5.http2.impl.nio.AbstractH2StreamMultiplexer.onException(AbstractH2StreamMultiplexer.java:661)
	at org.apache.hc.core5.http2.impl.nio.AbstractH2IOEventHandler.exception(AbstractH2IOEventHandler.java:91)
	at org.apache.hc.core5.http2.impl.nio.ClientH2IOEventHandler.exception(ClientH2IOEventHandler.java:39)
Caused by: org.apache.hc.core5.http.ConnectionClosedException: Connection is closed
	at org.apache.hc.core5.reactor.InternalDataChannel.onException(InternalDataChannel.java:162)
	at org.apache.hc.core5.reactor.InternalChannel.handleIOEvent(InternalChannel.java:55)
	at org.apache.hc.core5.reactor.SingleCoreIOReactor.processEvents(SingleCoreIOReactor.java:179)
	at org.apache.hc.core5.reactor.SingleCoreIOReactor.doExecute(SingleCoreIOReactor.java:128)
	at org.apache.hc.core5.reactor.AbstractSingleCoreIOReactor.execute(AbstractSingleCoreIOReactor.java:85)
	at org.apache.hc.core5.reactor.IOReactorWorker.run(IOReactorWorker.java:44)
	at java.base/java.lang.Thread.run(Thread.java:834)

StackTrace of the omitted exception:

org.apache.hc.core5.http2.H2ConnectionException: Frame size exceeds maximum
	at org.apache.hc.core5.http2.impl.nio.FrameInputBuffer.read(FrameInputBuffer.java:101)
	at org.apache.hc.core5.http2.impl.nio.AbstractH2StreamMultiplexer.onInput(AbstractH2StreamMultiplexer.java:440)
	at org.apache.hc.core5.http2.impl.nio.AbstractH2IOEventHandler.inputReady(AbstractH2IOEventHandler.java:65)
	at org.apache.hc.core5.http2.impl.nio.ClientH2IOEventHandler.inputReady(ClientH2IOEventHandler.java:39)
	at org.apache.hc.core5.reactor.InternalDataChannel.onIOEvent(InternalDataChannel.java:124)
	at org.apache.hc.core5.reactor.InternalChannel.handleIOEvent(InternalChannel.java:51)
	at org.apache.hc.core5.reactor.SingleCoreIOReactor.processEvents(SingleCoreIOReactor.java:179)
	at org.apache.hc.core5.reactor.SingleCoreIOReactor.doExecute(SingleCoreIOReactor.java:128)
	at org.apache.hc.core5.reactor.AbstractSingleCoreIOReactor.execute(AbstractSingleCoreIOReactor.java:85)
	at org.apache.hc.core5.reactor.IOReactorWorker.run(IOReactorWorker.java:44)
	at java.base/java.lang.Thread.run(Thread.java:834)

The complete session log can be found in the attachment hc5_session.log.