@Override
            public void onClose(WatcherException cause) {
                // Note: As per the JavaDoc of Watcher.onClose(), the method should not be implemented in a
                //       blocking way.
                if (closed) {
                    return;
                }
                logger.warn("[{}/{}] Service watcher is closed.", namespace, serviceName, cause);

                // Immediately retry on the first failure.
                scheduleRestartWithBackoff(++numServiceFailures);
            }
Watches the service. {@link Watcher} will retry automatically on failures by {@link KubernetesClient}.
kubernetes/src/main/java/com/linecorp/armeria/client/kubernetes/endpoints/KubernetesEndpointGroup.java