[HTTPCORE-414] HTTP Connection closed when polling an API every 5 seconds

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Invalid
• Affects Version/s: 4.4.4
• Component/s: HttpCore NIO
• Labels: connectionclosed http http304 httpcore

Environment

OS : Linux Ubuntu 14.04 LTS
Software : Java 1.8
Java source code available at the following link :
https://gist.github.com/dominiquemongelli/34e3588c5a1436276dff#file-httpcoreniosample
The java program uses the following libraries :
- httpclient 4.5.1
- httpcore-nio 4.4.4
- httpasyncclient 4.1
- httpcore 4.4.4

• Assignee: Unassigned
• Reporter: Dominique Mongelli
• Created: 18/Nov/15 14:42
• Updated: 05/Jul/16 07:46
• Resolved: 26/Nov/15 09:25

Description

Scenario to reproduce the bug :

• The java source code simulates 10 pollings on the following API http://www.typeunsafe.org/api/temperatures/69 (using httpasyncclient) with 5 seconds polling frequency.
• Compile and run the source code provided.
• Current result : after some polling correctly done, the execution throws the following exception :

  Exception in thread "main" java.util.concurrent.ExecutionException: org.apache.http.ConnectionClosedException: Connection closed
  	at org.apache.http.concurrent.BasicFuture.getResult(BasicFuture.java:70)
  	at org.apache.http.concurrent.BasicFuture.get(BasicFuture.java:80)
  	at HttpCoreSample.main(HttpCoreSample.java:31)
  	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
  	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
  	at java.lang.reflect.Method.invoke(Method.java:483)
  	at com.intellij.rt.execution.application.AppMain.main(AppMain.java:140)
  Caused by: org.apache.http.ConnectionClosedException: Connection closed
  	at org.apache.http.nio.protocol.HttpAsyncRequestExecutor.endOfInput(HttpAsyncRequestExecutor.java:321)
  	at org.apache.http.impl.nio.DefaultNHttpClientConnection.consumeInput(DefaultNHttpClientConnection.java:263)
  	at org.apache.http.impl.nio.client.InternalIODispatch.onInputReady(InternalIODispatch.java:81)
  	at org.apache.http.impl.nio.client.InternalIODispatch.onInputReady(InternalIODispatch.java:39)
  	at org.apache.http.impl.nio.reactor.AbstractIODispatch.inputReady(AbstractIODispatch.java:116)
  	at org.apache.http.impl.nio.reactor.BaseIOReactor.readable(BaseIOReactor.java:164)
  	at org.apache.http.impl.nio.reactor.AbstractIOReactor.processEvent(AbstractIOReactor.java:339)
  	at org.apache.http.impl.nio.reactor.AbstractIOReactor.processEvents(AbstractIOReactor.java:317)
  	at org.apache.http.impl.nio.reactor.AbstractIOReactor.execute(AbstractIOReactor.java:278)
  	at org.apache.http.impl.nio.reactor.BaseIOReactor.execute(BaseIOReactor.java:106)
  	at org.apache.http.impl.nio.reactor.AbstractMultiworkerIOReactor$Worker.run(AbstractMultiworkerIOReactor.java:590)
  	at java.lang.Thread.run(Thread.java:745)
  

Important things to mention :

• The issue does not occur with another API (for example API https://api.bitcoinaverage.com/ticker/global/EUR/)
• The issue is reproductible only with a 5 seconds polling frequency. If polling frequency is set to 10 seconds, then the issue is not reproductible anymore.
  The polling frequency can be updated via :

  Thread.sleep(POLLING_FREQUENCY_IN_MS);
  

• The API uses within the source code (http://www.typeunsafe.org/api/temperatures/69) can return a 304 http status when no data has been updated.
• The API uses a Varnish cache layer.

Issue Links

• links to: httpcoresample java source code