聊聊EurekaRibbonClientConfiguration-白红宇

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本文主要研究一下EurekaRibbonClientConfiguration

EurekaRibbonClientConfiguration

spring-cloud-netflix-eureka-client-2.0.0.RELEASE-sources.jar!/org/springframework/cloud/netflix/ribbon/eureka/EurekaRibbonClientConfiguration.java

/** * Preprocessor that configures defaults for eureka-discovered ribbon clients. Such as: * @zone, NIWSServerListClassName, DeploymentContextBasedVipAddresses, * NFLoadBalancerRuleClassName, NIWSServerListFilterClassName and more * * @author Spencer Gibb * @author Dave Syer * @author Ryan Baxter */@Configurationpublic class EurekaRibbonClientConfiguration {	private static final Log log = LogFactory.getLog(EurekaRibbonClientConfiguration.class);	@Value("${ribbon.eureka.approximateZoneFromHostname:false}")	private boolean approximateZoneFromHostname = false;	@RibbonClientName	private String serviceId = "client";	@Autowired(required = false)	private EurekaClientConfig clientConfig;	@Autowired(required = false)	private EurekaInstanceConfig eurekaConfig;	@Autowired	private PropertiesFactory propertiesFactory;	public EurekaRibbonClientConfiguration() {	}	public EurekaRibbonClientConfiguration(EurekaClientConfig clientConfig,			String serviceId, EurekaInstanceConfig eurekaConfig,			boolean approximateZoneFromHostname) {		this.clientConfig = clientConfig;		this.serviceId = serviceId;		this.eurekaConfig = eurekaConfig;		this.approximateZoneFromHostname = approximateZoneFromHostname;	}	@Bean	@ConditionalOnMissingBean	public IPing ribbonPing(IClientConfig config) {		if (this.propertiesFactory.isSet(IPing.class, serviceId)) {			return this.propertiesFactory.get(IPing.class, config, serviceId);		}		NIWSDiscoveryPing ping = new NIWSDiscoveryPing();		ping.initWithNiwsConfig(config);		return ping;	}	@Bean	@ConditionalOnMissingBean	public ServerList
     ribbonServerList(IClientConfig config, Provider
    
      eurekaClientProvider) {		if (this.propertiesFactory.isSet(ServerList.class, serviceId)) {			return this.propertiesFactory.get(ServerList.class, config, serviceId);		}		DiscoveryEnabledNIWSServerList discoveryServerList = new DiscoveryEnabledNIWSServerList(				config, eurekaClientProvider);		DomainExtractingServerList serverList = new DomainExtractingServerList(				discoveryServerList, config, this.approximateZoneFromHostname);		return serverList;	}	@Bean	public ServerIntrospector serverIntrospector() {		return new EurekaServerIntrospector();	}	@PostConstruct	public void preprocess() {		String zone = ConfigurationManager.getDeploymentContext()				.getValue(ContextKey.zone);		if (this.clientConfig != null && StringUtils.isEmpty(zone)) {			if (this.approximateZoneFromHostname && this.eurekaConfig != null) {				String approxZone = ZoneUtils						.extractApproximateZone(this.eurekaConfig.getHostName(false));				log.debug("Setting Zone To " + approxZone);				ConfigurationManager.getDeploymentContext().setValue(ContextKey.zone,						approxZone);			}			else {				String availabilityZone = this.eurekaConfig == null ? null						: this.eurekaConfig.getMetadataMap().get("zone");				if (availabilityZone == null) {					String[] zones = this.clientConfig							.getAvailabilityZones(this.clientConfig.getRegion());					// Pick the first one from the regions we want to connect to					availabilityZone = zones != null && zones.length > 0 ? zones[0]							: null;				}				if (availabilityZone != null) {					// You can set this with archaius.deployment.* (maybe requires					// custom deployment context)?					ConfigurationManager.getDeploymentContext().setValue(ContextKey.zone,							availabilityZone);				}			}		}		RibbonUtils.initializeRibbonDefaults(serviceId);	}}复制代码

创建了NIWSDiscoveryPing、DomainExtractingServerList、EurekaServerIntrospector

初始化之后调用RibbonUtils.initializeRibbonDefaults(serviceId)

NIWSDiscoveryPing

ribbon-eureka-2.2.5-sources.jar!/com/netflix/niws/loadbalancer/NIWSDiscoveryPing.java

/** * "Ping" Discovery Client * i.e. we dont do a real "ping". We just assume that the server is up if Discovery Client says so * @author stonse * */public class NIWSDiscoveryPing extends AbstractLoadBalancerPing {	        		BaseLoadBalancer lb = null; 				public NIWSDiscoveryPing() {		}				public BaseLoadBalancer getLb() {			return lb;		}		/**		 * Non IPing interface method - only set this if you care about the "newServers Feature"		 * @param lb		 */		public void setLb(BaseLoadBalancer lb) {			this.lb = lb;		}		public boolean isAlive(Server server) {		    boolean isAlive = true;		    if (server!=null && server instanceof DiscoveryEnabledServer){	            DiscoveryEnabledServer dServer = (DiscoveryEnabledServer)server;	            	            InstanceInfo instanceInfo = dServer.getInstanceInfo();	            if (instanceInfo!=null){	                	                InstanceStatus status = instanceInfo.getStatus();	                if (status!=null){	                    isAlive = status.equals(InstanceStatus.UP);	                }	            }	        }		    return isAlive;		}        @Override        public void initWithNiwsConfig(                IClientConfig clientConfig) {        }		}复制代码

NIWSDiscoveryPing通过获取实例的eureka状态来判断是否健康

DomainExtractingServerList

spring-cloud-netflix-eureka-client-2.0.0.RELEASE-sources.jar!/org/springframework/cloud/netflix/ribbon/eureka/DomainExtractingServerList.java

public class DomainExtractingServerList implements ServerList
    
      {	private ServerList
     
       list;	private final RibbonProperties ribbon;	private boolean approximateZoneFromHostname;	public DomainExtractingServerList(ServerList
      
        list,			IClientConfig clientConfig, boolean approximateZoneFromHostname) {		this.list = list;		this.ribbon = RibbonProperties.from(clientConfig);		this.approximateZoneFromHostname = approximateZoneFromHostname;	}	@Override	public List
       
         getInitialListOfServers() {		List
        
          servers = setZones(this.list				.getInitialListOfServers());		return servers;	}	@Override	public List
         
           getUpdatedListOfServers() { List
          
            servers = setZones(this.list .getUpdatedListOfServers()); return servers; } private List
           
             setZones(List
            
              servers) { List
             
               result = new ArrayList<>(); boolean isSecure = this.ribbon.isSecure(true); boolean shouldUseIpAddr = this.ribbon.isUseIPAddrForServer(); for (DiscoveryEnabledServer server : servers) { result.add(new DomainExtractingServer(server, isSecure, shouldUseIpAddr, this.approximateZoneFromHostname)); } return result; }}class DomainExtractingServer extends DiscoveryEnabledServer { private String id; @Override public String getId() { return id; } @Override public void setId(String id) { this.id = id; } public DomainExtractingServer(DiscoveryEnabledServer server, boolean useSecurePort, boolean useIpAddr, boolean approximateZoneFromHostname) { // host and port are set in super() super(server.getInstanceInfo(), useSecurePort, useIpAddr); if (server.getInstanceInfo().getMetadata().containsKey("zone")) { setZone(server.getInstanceInfo().getMetadata().get("zone")); } else if (approximateZoneFromHostname) { setZone(ZoneUtils.extractApproximateZone(server.getHost())); } else { setZone(server.getZone()); } setId(extractId(server)); setAlive(server.isAlive()); setReadyToServe(server.isReadyToServe()); } private String extractId(Server server) { if (server instanceof DiscoveryEnabledServer) { DiscoveryEnabledServer enabled = (DiscoveryEnabledServer) server; InstanceInfo instance = enabled.getInstanceInfo(); if (instance.getMetadata().containsKey("instanceId")) { return instance.getHostName()+":"+instance.getMetadata().get("instanceId"); } } return super.getId(); }}复制代码

getInitialListOfServers及getUpdatedListOfServers都调用了setZones从eureka的metadata读取zone

EurekaServerIntrospector

spring-cloud-netflix-eureka-client-2.0.0.RELEASE-sources.jar!/org/springframework/cloud/netflix/ribbon/eureka/EurekaServerIntrospector.java

public class EurekaServerIntrospector extends DefaultServerIntrospector {	@Override	public boolean isSecure(Server server) {		if (server instanceof DiscoveryEnabledServer) {			DiscoveryEnabledServer discoveryServer = (DiscoveryEnabledServer) server;			return discoveryServer.getInstanceInfo().isPortEnabled(InstanceInfo.PortType.SECURE);		}		return super.isSecure(server);	}	@Override	public Map
    
      getMetadata(Server server) {		if (server instanceof DiscoveryEnabledServer) {			DiscoveryEnabledServer discoveryServer = (DiscoveryEnabledServer) server;			return discoveryServer.getInstanceInfo().getMetadata();		}		return super.getMetadata(server);	}}复制代码

这里从eureka的instanceInfo获取metadata

小结

EurekaRibbonClientConfiguration主要是给ribbon配置eureka相关的特性，主要是NIWSDiscoveryPing、DomainExtractingServerList、EurekaServerIntrospector这几个：

其中NIWSDiscoveryPing通过eureka中instance的状态来判断是否ping的通

DomainExtractingServerList提供getInitialListOfServers以及getUpdatedListOfServers方法

EurekaServerIntrospector主要是通过instanceInfo获取metadata

序

EurekaRibbonClientConfiguration

NIWSDiscoveryPing

DomainExtractingServerList

EurekaServerIntrospector

小结

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