Ribbon 和 Eureka 的集成

        配置文件基本采用《Eureka 的 Application Client 客户端的运行示例》Eureka Application Client 客户端配置。另外增添以下配置项：

• 启用客户端负载均衡器并将其配置为 DynamicServerListLoadBalancer 或其子类(这个无须在配置中体现，因为这个是 Eureka 和 Ribbon 集成默认为 true 的)。
• 将 ServerList 配置为 com.netflix.niws.loadbalancer.DiscoveryEnabledNIWSServerList。
• 配置服务器(负载均衡节点)的刷新频率(可选。默认是为 30 秒)。
• 为 Eureka 客户端配置服务器的虚拟地址(VIP 地址)，并确保这个地址匹配到服务器(Application Service)注册 Eureka Server 时所用到的那个。

myclient.ribbon.NIWSServerListClassName=com.netflix.niws.loadbalancer.DiscoveryEnabledNIWSServerList


# refresh every minute 
myclient.ribbon.ServerListRefreshInterval=60000


# movieservice is the virtual address that the target server(s) uses to register with Eureka server
myclient.ribbon.DeploymentContextBasedVipAddresses=movieservice
        配置文件的初始化仍然采用《Eureka 的 Application Client 客户端的运行示例》中的配置初始化方法：
		// Register with Eureka
		DiscoveryManager.getInstance().initComponent(
				new MyDataCenterInstanceConfig(),
				new DefaultEurekaClientConfig());
		ApplicationInfoManager.getInstance().setInstanceStatus(
				InstanceStatus.UP);

		// get LoadBalancer instance from configuration, properties file
		DynamicServerListLoadBalancer lb = (DynamicServerListLoadBalancer) ClientFactory.getNamedLoadBalancer("myclient");
		// use RandomRule ‘s RandomRule algorithm to get a random server from lb ‘s server list
		RandomRule randomRule = new RandomRule();
		Server randomAlgorithmServer = randomRule.choose(lb, null);
		logger.debug("random algorithm server host:" + randomAlgorithmServer.getHost() + ";port:" + randomAlgorithmServer.getPort());

/*
 * Copyright 2012 Netflix, Inc.
 *
 *    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.
 */


package com.netflix.eureka;


import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.net.InetSocketAddress;
import java.net.Socket;
import java.util.Date;
import java.util.Iterator;
import java.util.List;


import org.slf4j.Logger;
import org.slf4j.LoggerFactory;


import com.netflix.appinfo.ApplicationInfoManager;
import com.netflix.appinfo.InstanceInfo.InstanceStatus;
import com.netflix.appinfo.MyDataCenterInstanceConfig;
import com.netflix.client.ClientFactory;
import com.netflix.discovery.DefaultEurekaClientConfig;
import com.netflix.discovery.DiscoveryManager;
import com.netflix.loadbalancer.DynamicServerListLoadBalancer;
import com.netflix.loadbalancer.RandomRule;
import com.netflix.loadbalancer.Server;


/**
 * Sample Eureka client that discovers the service using Eureka and sends
 * requests.
 *
 * @author Karthik Ranganathan
 *
 */
public class SampleEurekaRibbonClient {
	private static final Logger logger = LoggerFactory
			.getLogger(SampleEurekaRibbonClient.class);


	public void sendRequestToServiceUsingEureka() {


		// Register with Eureka
		DiscoveryManager.getInstance().initComponent(
				new MyDataCenterInstanceConfig(),
				new DefaultEurekaClientConfig());
		ApplicationInfoManager.getInstance().setInstanceStatus(
				InstanceStatus.UP);
		// get LoadBalancer instance from configuration, properties file
		DynamicServerListLoadBalancer lb = (DynamicServerListLoadBalancer) ClientFactory.getNamedLoadBalancer("myclient");
		// show all servers in the list
		List<Server> list = lb.getServerList(false);
		Iterator<Server> it = list.iterator();
		while (it.hasNext()) {
			Server server = it.next();
			logger.debug("application service host:" + server.getHost() + ";port=" + server.getPort());
		}
		// use RandomRule ‘s RandomRule algorithm to get a random server from lb ‘s server list
		RandomRule randomRule = new RandomRule();
		Server randomAlgorithmServer = randomRule.choose(lb, null);
		logger.debug("random algorithm server host:" + randomAlgorithmServer.getHost() + ";port:" + randomAlgorithmServer.getPort());
		// communicate with the server
		Socket s = new Socket();
		try {
			s.connect(new InetSocketAddress(randomAlgorithmServer.getHost(), randomAlgorithmServer.getPort()));
		} catch (IOException e) {
			logger.error("Could not connect to the server :"
					+ randomAlgorithmServer.getHost() + " at port " + randomAlgorithmServer.getPort());
		}
		try {
			logger.debug("Connected to server. Sending a sample request");
			PrintStream out = new PrintStream(s.getOutputStream());
			out.println("Sample request " + new Date());
			String str = null;
			logger.debug("Waiting for server response..");
			BufferedReader rd = new BufferedReader(new InputStreamReader(
					s.getInputStream()));
			str = rd.readLine();
			if (str != null) {
				logger.debug("Received response from server. Communication all fine using Eureka :");
				logger.debug("Exiting the client. Demo over..");
			}
			rd.close();
		} catch (IOException e) {
			e.printStackTrace();
			logger.error(e.getMessage(), e);
		}
		this.unRegisterWithEureka();
	}


	public void unRegisterWithEureka() {
		// Un register from eureka.
		DiscoveryManager.getInstance().shutdownComponent();
	}


	public static void main(String[] args) {
		SampleEurekaRibbonClient sampleEurekaRibbonClient = new SampleEurekaRibbonClient();
		sampleEurekaRibbonClient.sendRequestToServiceUsingEureka();


	}
}

• https://github.com/Netflix/ribbon/wiki/Programmers-Guide

Ribbon 和 Eureka 的集成

原文：http://blog.csdn.net/defonds/article/details/38016301