resilience4j-retry:1.7.1 - does not retry websocket connection

Question

I am trying to connect to a remote websocket endpoint (inside spring boot app), and if it throws an Exception I use resilience4j-retry v1.7.7 with JDK 8 to retry connection. However resilience4j-retry tries to connect once and if it fails do not retry. What have I done wrong, the connection is called on ApplicationReadyEvent.

    @Autowired
    private WsConnector connector;

    @Override
    public void onApplicationEvent(ApplicationReadyEvent event) {
        RetryConfig config = RetryConfig.custom()
                .maxAttempts(5)
                .waitDuration(Duration.ofSeconds(5))
                .build();

        RetryRegistry registry = RetryRegistry.of(config);
        Retry retry = registry.retry("retryableSupplier", config);

        CheckedFunction0<String> retryableSupplier = Retry.decorateCheckedSupplier(retry, connector::startConnection);
        try {
            System.out.println("retrying " + retryableSupplier.apply());
        } catch (Throwable throwable) {
            throwable.printStackTrace();
        }

        Retry.EventPublisher publisher = retry.getEventPublisher();
        publisher.onRetry(event1 -> System.out.println(event1.toString()));
        publisher.onSuccess(event2 -> System.out.println(event2.toString()));
    }

    @Service
    public class WsConnector {
        public String startConnection() throws Exception {
            WebSocketContainer container = ContainerProvider.getWebSocketContainer();
            WSClient client = new WSClient();
            container.connectToServer(client, new URI("ws://viewpoint:8080/ping"));
            return "Connected";
        }
    }

score 0 · Accepted Answer · answered Dec 13 '21 at 10:59

Following code worked,

     @Override
    public void onApplicationEvent(ApplicationReadyEvent event) {
        RetryConfig config = RetryConfig.custom()
                .maxAttempts(5)
                .waitDuration(Duration.ofSeconds(5))
                .build();

        RetryRegistry registry = RetryRegistry.of(config);
        Retry retry = registry.retry("retryableSupplier", config);
        CheckedFunction0<String> checkedSupplier = Retry.decorateCheckedSupplier(retry, connector::startConnection);

        Retry.EventPublisher publisher = retry.getEventPublisher();
        publisher.onRetry(event1 -> System.out.println("Retrying: " + event1.toString()));
        publisher.onSuccess(event2 -> System.out.println("Retrying Success: " +event2.toString()));

        Try<String> result = Try.of(checkedSupplier).recover((throwable -> "I am recovered"));
        System.out.println("result: " + result);
    }

The issue was with the event EventPublisher, it was working however was not visible as I initialized EventPublisher after the retry. So the code in the question will also work provided EventPublisher is initialized before retry is initiated. I liked above code more clean.

resilience4j-retry:1.7.1 - does not retry websocket connection

1 Answers1