这个问题通常是因为你的程序没有正确地关闭ManagedChannel导致的。可以尝试在你的代码中关闭ManagedChannel或在BeamOptions中设置一个ShutdownHook。以下是示例代码：

//在管道中设置一个ShutdownHook
public class MyOptions extends PipelineOptions {
  @Description("MyOption")
  @Default.String("myValue")
  String getMyOption();
  void setMyOption(String value);

  @Description("Set shutdown hook")
  @Default.Boolean(true)
  Boolean getSetShutdownHook();
  void setSetShutdownHook(Boolean value);
}

MyOptions options = PipelineOptionsFactory.fromArgs(args).withValidation().as(MyOptions.class);
if (options.getSetShutdownHook()) {
  //在程序关闭时自动关闭ManagedChannel
  LifecycleManager.addShutdownHook(() -> {
    try {
      grpcCleanup.run(); //关闭gRPC channel和executor
    } catch (Exception e) {
      // log exception
    }
  });
}

// 在代码中主动关闭ManagedChannel
ManagedChannel channel = ManagedChannelBuilder.forAddress(host, port).build();
try {
  // do something with channel
} finally {
  channel.shutdown();
}