Spring Cloud Zookeeper and Service Registry

Spring Cloud Zookeeper 实现了 ServiceRegistry 接口，这允许开发人员以编程方式注册任意服务。

Spring Cloud Zookeeper implements the ServiceRegistry interface, letting developers register arbitrary services in a programmatic way.

ServiceInstanceRegistration 类提供了一个 builder() 方法，该方法可以创建一个`Registration` 对象，该对象可由 ServiceRegistry 使用，如下例所示：

The ServiceInstanceRegistration class offers a builder() method to create a Registration object that can be used by the ServiceRegistry, as shown in the following example:

@Autowired
private ZookeeperServiceRegistry serviceRegistry;

public void registerThings() {
    ZookeeperRegistration registration = ServiceInstanceRegistration.builder()
            .defaultUriSpec()
            .address("anyUrl")
            .port(10)
            .name("/a/b/c/d/anotherservice")
            .build();
    this.serviceRegistry.register(registration);
}

Instance Status

Netflix Eureka 支持将实例`OUT_OF_SERVICE` 注册在服务器上。这些实例不会作为活动服务实例返回。这对蓝/绿部署等行为很有用。（请注意，Curator Service Discovery 方法不支持此行为。）Spring Cloud Zookeeper 利用灵活的有效负载实现了`OUT_OF_SERVICE`，方法是更新一些特定元数据，然后在 Spring Cloud LoadBalancer ZookeeperServiceInstanceListSupplier 中根据该元数据进行筛选。ZookeeperServiceInstanceListSupplier 会筛选出所有不等于 UP 的非空实例状态。如果实例状态字段为空，则为了向后兼容，它会被视为 UP。要更改实例的状态，请使用 OUT_OF_SERVICE 向 ServiceRegistry 实例状态执行器端点发出 POST，如下例所示：

Netflix Eureka supports having instances that are OUT_OF_SERVICE registered with the server. These instances are not returned as active service instances. This is useful for behaviors such as blue/green deployments. (Note that the Curator Service Discovery recipe does not support this behavior.) Taking advantage of the flexible payload has let Spring Cloud Zookeeper implement OUT_OF_SERVICE by updating some specific metadata and then filtering on that metadata in the Spring Cloud LoadBalancer ZookeeperServiceInstanceListSupplier. The ZookeeperServiceInstanceListSupplier filters out all non-null instance statuses that do not equal UP. If the instance status field is empty, it is considered to be UP for backwards compatibility. To change the status of an instance, make a POST with OUT_OF_SERVICE to the ServiceRegistry instance status actuator endpoint, as shown in the following example:

$ http POST http://localhost:8081/serviceregistry status=OUT_OF_SERVICE

前一个示例使用 [role="bare"][role="bare"]https://httpie.org 中的 http 命令。

The preceding example uses the http command from [role="bare"]https://httpie.org.