Ribbon

Ribbon is a client side IPC library that is battle-tested in cloud. It provides the following features

• Load balancing
• Fault tolerance
• Multiple protocol (HTTP, TCP, UDP) support in an asynchronous and reactive model
• Caching and batching

To get ribbon binaries, go to maven central. Here is an example to add dependency in Maven:

<dependency>
    <groupId>com.netflix.ribbon</groupId>
    <artifactId>ribbon</artifactId>
    <version>2.0-RC1</version>
</dependency>

Modules

• ribbon: APIs that integrate load balancing, fault tolerance, caching/batching on top of other ribbon modules and Hystrix
• ribbon-loadbalancer: Load balancer APIs that can be used independently or with other modules
• ribbon-eureka: APIs using Eureka client to provide dynamic server list for cloud
• ribbon-transport: Transport clients that support HTTP, TCP and UDP protocols using RxNetty with load balancing capability
• ribbon-httpclient: REST client built on top of Apache HttpClient integrated with load balancers (deprecated and being replaced by ribbon module)
• ribbon-example: Examples
• ribbon-core: Client configuration APIs and other shared APIs

Release notes

See https://github.com/Netflix/ribbon/releases

Code example

Access HTTP resource using template (full example)

HttpResourceGroup httpResourceGroup = Ribbon.createHttpResourceGroup("movieServiceClient",
            ClientOptions.create()
                    .withMaxAutoRetriesNextServer(3)
                    .withConfigurationBasedServerList("localhost:8080,localhost:8088"));
HttpRequestTemplate<ByteBuf> recommendationsByUserIdTemplate = httpResourceGroup.newTemplateBuilder("recommendationsByUserId", ByteBuf.class)
            .withMethod("GET")
            .withUriTemplate("/users/{userId}/recommendations")
            .withFallbackProvider(new RecommendationServiceFallbackHandler())
            .withResponseValidator(new RecommendationServiceResponseValidator())
            .build();
Observable<ByteBuf> result = recommendationsByUserIdTemplate.requestBuilder()
                        .withRequestProperty("userId", “user1")
                        .build()
                        .observe();

Access HTTP resource using annotations (full example)

public interface MovieService {
    @Http(
            method = HttpMethod.GET,
            uriTemplate = "/users/{userId}/recommendations",
            )
    RibbonRequest<ByteBuf> recommendationsByUserId(@Var("userId") String userId);
}

MovieService movieService = Ribbon.from(MovieService.class);
Observable<ByteBuf> result = movieService.recommendationsByUserId("user1").observe();

Create an AWS-ready load balancer with Eureka dynamic server list and zone affinity enabled

        IRule rule = new AvailabilityFilteringRule();
        ServerList<DiscoveryEnabledServer> list = new DiscoveryEnabledNIWSServerList("MyVIP:7001");
        ServerListFilter<DiscoveryEnabledServer> filter = new ZoneAffinityServerListFilter<DiscoveryEnabledServer>();
        ZoneAwareLoadBalancer<DiscoveryEnabledServer> lb = LoadBalancerBuilder.<DiscoveryEnabledServer>newBuilder()
                .withDynamicServerList(list)
                .withRule(rule)
                .withServerListFilter(filter)
                .buildDynamicServerListLoadBalancer();   
        DiscoveryEnabledServer server = lb.chooseServer();         

Use LoadBalancerCommand to load balancing IPC calls made by HttpURLConnection (full example)

CommandBuilder.<String>newBuilder()
        .withLoadBalancer(LoadBalancerBuilder.newBuilder().buildFixedServerListLoadBalancer(serverList))
        .build(new LoadBalancerExecutable<String>() {
            @Override
            public String run(Server server) throws Exception {
                URL url = new URL("http://" + server.getHost() + ":" + server.getPort() + path);
                HttpURLConnection conn = (HttpURLConnection) url.openConnection();
                return conn.getResponseMessage();
            }
        }).execute();

Questions?

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