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,
            uri = "/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();

License

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

Questions?

Email ribbon-users@googlegroups.com or join us

tbak/ribbon