Unhandled exception: java.util.concurrent.RejectedExecutionException when closing LocalPortForward

[matteriben]

Describe the bug

Closing an instance of LocalPortForward sometimes results in an unhandled RejectedExecutionException. This does not appear to be causing any problem other than producing unnecessary exception messages.

Fabric8 Kubernetes Client version

6.12.1

Steps to reproduce

Run nginx:

kubectl run nginx --image=nginx

Then run this test:

public class PortForwardTest {
    KubernetesClient client = new KubernetesClientBuilder().build();
    @Test
    void test() throws Exception {
        for (int i = 0; i < 1000; i++) {
            try (LocalPortForward lpf = client.pods().inNamespace("default").withName("nginx").portForward(80)) {
                new URL("http://localhost:" + lpf.getLocalPort()).openStream().close();
            }
        }
    }
}

Expected behavior

No unhandled exceptions.

Runtime

other (please specify in additional context)

Kubernetes API Server version

other (please specify in additional context)

Environment

Linux

Fabric8 Kubernetes Client Logs

2024-08-02 01:29:44,480 ERROR [io.ver.cor.imp.ContextImpl] (vert.x-eventloop-thread-9) Unhandled exception: java.util.concurrent.RejectedExecutionException
	at io.fabric8.kubernetes.client.utils.internal.SerialExecutor.execute(SerialExecutor.java:47)
	at io.fabric8.kubernetes.client.dsl.internal.PortForwarderWebsocketListener.onMessage(PortForwarderWebsocketListener.java:128)
	at io.fabric8.kubernetes.client.vertx.VertxWebSocket.lambda$init$0(VertxWebSocket.java:48)
	at io.vertx.core.http.impl.WebSocketImplBase$FrameAggregator.handleBinaryFrame(WebSocketImplBase.java:658)
	at io.vertx.core.http.impl.WebSocketImplBase$FrameAggregator.handle(WebSocketImplBase.java:603)
	at io.vertx.core.http.impl.WebSocketImplBase$FrameAggregator.handle(WebSocketImplBase.java:589)
	at io.vertx.core.impl.ContextInternal.dispatch(ContextInternal.java:279)
	at io.vertx.core.http.impl.WebSocketImplBase.receiveFrame(WebSocketImplBase.java:534)
	at io.vertx.core.streams.impl.InboundBuffer.handleEvent(InboundBuffer.java:255)
	at io.vertx.core.streams.impl.InboundBuffer.drain(InboundBuffer.java:242)
	at io.vertx.core.streams.impl.InboundBuffer.lambda$fetch$0(InboundBuffer.java:295)
	at io.vertx.core.impl.ContextInternal.dispatch(ContextInternal.java:279)
	at io.vertx.core.impl.ContextInternal.dispatch(ContextInternal.java:261)
	at io.vertx.core.impl.ContextInternal.lambda$runOnContext$0(ContextInternal.java:59)
	at io.netty.util.concurrent.AbstractEventExecutor.runTask(AbstractEventExecutor.java:173)
	at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:166)
	at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:470)
	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:569)
	at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:997)
	at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	at java.base/java.lang.Thread.run(Thread.java:1583)

Additional context

serverVersion:
  buildDate: "2024-02-14T22:25:42Z"
  compiler: gc
  gitCommit: 4b8e819355d791d96b7e9d9efe4cbafae2311c88
  gitTreeState: clean
  gitVersion: v1.29.2
  goVersion: go1.21.7
  major: "1"
  minor: "29"
  platform: linux/arm64

[matteriben]

Thank you @shawkins !