Agfdhyk

Did anyone succeeded using failover transport utilizing active/standby Active MQ (Amazon MQ to be precise) when configuring websocket stomp broker relay ?

I did create following TcpClient, but it implements round-robin algorithm over given endpoints, which causes some errors when actually standby instance is being selected:

Transport failure: epoll_ctl(..) failed: No such file or directory

Here's my current implementation:

public class StompTcpFactory implements NetStreams.TcpClientFactory<Message<byte>, Message<byte>> {

    private final Environment environment = new Environment(new SynchronousDispatcherConfigReader());

    private final List<URI> endpoints;

    private final boolean isSsl;



    public StompTcpFactory(List<String> endpoints) {

        this.endpoints = endpoints.stream()

                .map(e -> contains(e, "://") ? e : "fake://" + e)

                .map(URI::create)

                .collect(toList());

        isSsl = this.endpoints.stream().anyMatch(StompTcpFactory::isSsl);



        boolean anyNotSsl = this.endpoints.stream().anyMatch(not(StompTcpFactory::isSsl));

        if (isSsl && anyNotSsl)

            throw new IllegalArgumentException("Cannot configure STOMP to use SSL and regular connections at the same time: " + endpoints);

    }



    @Override

    public Spec.TcpClientSpec<Message<byte>, Message<byte>> apply(Spec.TcpClientSpec<Message<byte>, Message<byte>> tcpClientSpec) {

        return tcpClientSpec

                .env(environment)

                .codec(new Reactor2StompCodec(new StompEncoder(), new StompDecoder()))

                .ssl(isSsl ? new SslOptions() : null)

                .connect(new InetSocketAddressSupplier(endpoints));

    }



    private static boolean isSsl(URI endpoint) {

        return containsIgnoreCase(endpoint.getScheme(), "ssl");

    }



    private static class SynchronousDispatcherConfigReader implements ConfigurationReader {

        @Override

        public ReactorConfiguration read() {

            return new ReactorConfiguration(emptyList(), "sync", new Properties());

        }

    }



}

with following supplier:

public class InetSocketAddressSupplier implements Supplier<InetSocketAddress> {



    private static final AtomicInteger counter = new AtomicInteger(0);



    private final Logger logger = LoggerFactory.getLogger(getClass());

    private final List<URI> endpoints;



    public InetSocketAddressSupplier(List<URI> endpoints) {

        this.endpoints = endpoints;

    }



    @Override

    public InetSocketAddress get() {

        int endpointIndex = counter.getAndUpdate(i -> ++i % endpoints.size());

        URI endpoint = endpoints.get(endpointIndex);



        logger.info("nnConnecting to broker[{}]: {}:{}nn", endpointIndex, endpoint.getHost(), endpoint.getPort());

        return new InetSocketAddress(endpoint.getHost(), endpoint.getPort());

    }



}

And here's the broker configuration:

@Override

public void configureMessageBroker(MessageBrokerRegistry registry) {

    String environment = configService.getString(ENVIRONMENT);



    String user = configService.getString(WEBSOCKET_EXTERNAL_BROKER_USER);

    String password = configService.getString(WEBSOCKET_EXTERNAL_BROKER_PASSWORD);

    registry

            .enableStompBrokerRelay("/queue", "/topic")

            .setRelayHost(UNUSED_RELAY_HOST)

            .setClientLogin(user)

            .setClientPasscode(password)

            .setSystemLogin(user)

            .setSystemPasscode(password)

            .setUserDestinationBroadcast(format("/topic/%s-unresolved-user-destination", environment))

            .setUserRegistryBroadcast(format("/topic/%s-simp-user-registry", environment))

            .setTcpClient(createTcpClient());



    registry.setApplicationDestinationPrefixes(format("/%s-websocket-app", environment));

}





private TcpOperations<byte> createTcpClient() {

    List<String> endpoints = asList(configService.getStringArray(WEBSOCKET_EXTERNAL_BROKER_ENDPOINTS));

    logger.info("Configuring websocket brokers to: {}", endpoints);

    return new Reactor2TcpClient<>(new StompTcpFactory(endpoints));

}