Stopping informer does not cancel the resyncFuture nor it shutdown the resyncExecutor

[akram]

While trying to stop a set of informers and start new ones, there is remaining task trying to schedule in an executor:

2021-04-19 16:14:50 SEVERE  hudson.init.impl.InstallUncaughtExceptionHandler$DefaultUncaughtExceptionHandler uncaughtException A thread (informer-controller-ImageStream/460) died unexpectedly due to an uncaught exception, this may leave your Jenkins in a bad way and is usually indicative of a bug in the code.

Incidently with the error, I have several errors of this type showing that a task is still trying to be submitted on an open executor.

2021-04-19 16:15:01 WARNING io.fabric8.kubernetes.client.dsl.internal.WatcherWebSocketListener onFailure Exec Failure
java.io.InterruptedIOException: executor rejected
	at okhttp3.RealCall$AsyncCall.executeOn(RealCall.java:186)
	at okhttp3.Dispatcher.promoteAndExecute(Dispatcher.java:186)
	at okhttp3.Dispatcher.enqueue(Dispatcher.java:137)
	at okhttp3.RealCall.enqueue(RealCall.java:127)
	at okhttp3.internal.ws.RealWebSocket.connect(RealWebSocket.java:193)
[...]
	at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: java.util.concurrent.RejectedExecutionException: Task okhttp3.RealCall$AsyncCall@6285bec1 rejected from java.util.concurrent.ThreadPoolExecutor@509c2579[Terminated, pool size = 0, active threads = 0, queued tasks = 0, completed tasks = 15]
	at java.base/java.util.concurrent.ThreadPoolExecutor$AbortPolicy.rejectedExecution(ThreadPoolExecutor.java:2055)
	at java.base/java.util.concurrent.ThreadPoolExecutor.reject(ThreadPoolExecutor.java:825)
	at java.base/java.util.concurrent.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:1355)
	at okhttp3.RealCall$AsyncCall.executeOn(RealCall.java:183)
	... 104 more

After investigations, I see that the resyncFuture https://github.com/fabric8io/kubernetes-client/blob/master/kubernetes-client/src/main/java/io/fabric8/kubernetes/client/informers/cache/Controller.java#L103 of informers are not canceled not their executors are shutdown.

[akram]

fixed by #3017