Nacos服务跨分组调用
一、 问题背景
nacos有两种服务隔离的机制,一个是空间namespace,一般我们用namespace区分环境,另外一个是分组group,nacos的默认调用机制是同namespace下的同group的服务才可以相互调用;
那现在有个问题: 在测试阶段,由于测试环境和开发环境数据库等不一致,在测试出bug后,开发人员需要连接到测试环境上复线定位bug,但是如果开发人员本地启动测试环境,那么就会导致测试环境服务多了个本地的实例,这样测试在调用这个服务的时候很有可能就会访问这个本地服务,导致服务异常,所以一般我们都会采用本地服务自定义group分组的方式注册;
一般来说,一个服务关连多个其他服务,开发人员就需要把所有相关的服务都注册到自定义的group分组中,这样才能保证接口通常,但是起很多服务又会导致电脑内存消耗巨大,所以就想着能不能只启动存在问题的那个服务,其他关联服务还是使用测试环境的服务,基于这种考虑才想实现跨分组调用,减少无关服务的启动.
二、实现方案
1.版本要求
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
<version>2021.0.4.0</version>
</dependency>
如果 Java 项目的 nacos discovery 版本用的是 2021以上，则不需要重写 Ribbon 的负载均衡类，因为该版本的 Nacos 不依赖 Ribbon,只需要重写服务发现即可
2.重写服务发现
public class NacosServiceDiscoveryV2 extends NacosServiceDiscovery {
public NacosServiceDiscoveryV2(NacosDiscoveryProperties discoveryProperties, NacosServiceManager nacosServiceManager) {
super(discoveryProperties, nacosServiceManager);
this.discoveryProperties = discoveryProperties;
this.nacosServiceManager = nacosServiceManager;
}
private NacosDiscoveryProperties discoveryProperties;
private NacosServiceManager nacosServiceManager;
// 重写该方法
public List<ServiceInstance> getInstances(String serviceId) throws NacosException {
String group = this.discoveryProperties.getGroup();
// 优先保证同分组下的服务调用
List<Instance> instances = this.namingService().selectInstances(serviceId, group, true);
if (CollUtil.isEmpty(instances)) {
// 如果同分组下找不到服务,那么就从默认分组下找服务
instances = this.namingService().selectInstances(serviceId, "DEFAULT_GROUP", true);
}
return hostToServiceInstanceList(instances, serviceId);
}
public List<String> getServices() throws NacosException {
String group = this.discoveryProperties.getGroup();
ListView<String> services = this.namingService().getServicesOfServer(1, Integer.MAX_VALUE, group);
return services.getData();
}
public static List<ServiceInstance> hostToServiceInstanceList(List<Instance> instances, String serviceId) {
List<ServiceInstance> result = new ArrayList(instances.size());
Iterator var3 = instances.iterator();
while (var3.hasNext()) {
Instance instance = (Instance) var3.next();
ServiceInstance serviceInstance = hostToServiceInstance(instance, serviceId);
if (serviceInstance != null) {
result.add(serviceInstance);
}
}
return result;
}
public static ServiceInstance hostToServiceInstance(Instance instance, String serviceId) {
if (instance != null && instance.isEnabled() && instance.isHealthy()) {
NacosServiceInstance nacosServiceInstance = new NacosServiceInstance();
nacosServiceInstance.setHost(instance.getIp());
nacosServiceInstance.setPort(instance.getPort());
nacosServiceInstance.setServiceId(serviceId);
nacosServiceInstance.setInstanceId(instance.getInstanceId());
Map<String, String> metadata = new HashMap();
metadata.put("nacos.instanceId", instance.getInstanceId());
metadata.put("nacos.weight", instance.getWeight() + "");
metadata.put("nacos.healthy", instance.isHealthy() + "");
metadata.put("nacos.cluster", instance.getClusterName() + "");
if (instance.getMetadata() != null) {
metadata.putAll(instance.getMetadata());
}
metadata.put("nacos.ephemeral", String.valueOf(instance.isEphemeral()));
nacosServiceInstance.setMetadata(metadata);
if (metadata.containsKey("secure")) {
boolean secure = Boolean.parseBoolean((String) metadata.get("secure"));
nacosServiceInstance.setSecure(secure);
}
return nacosServiceInstance;
} else {
return null;
}
}
private NamingService namingService() {
return this.nacosServiceManager.getNamingService();
}
}
3.重写自动配置类,更早的加载到Nacos容器中
@Configuration(proxyBeanMethods = false)
@ConditionalOnDiscoveryEnabled
@ConditionalOnNacosDiscoveryEnabled
@AutoConfigureBefore({NacosDiscoveryAutoConfiguration.class})
public class NacosDiscoveryAutoConfigurationV2 {
@Bean
@ConditionalOnMissingBean
public NacosServiceDiscovery nacosServiceDiscovery(NacosDiscoveryProperties nacosDiscoveryProperties, NacosServiceManager nacosServiceManager) {
return new NacosServiceDiscoveryV2(nacosDiscoveryProperties, nacosServiceManager);
}
}
其他版本的nacos的话,可能需要借助Ribbon负载均衡来处理跨分组调用,具体可参考以下:
参考:
