Add some documentation about the property eureka.client.refresh.enable

docs/src/main/asciidoc/spring-cloud-netflix.adoc

@@ -324,6 +324,19 @@ eureka.instance.metadataMap.zone = zone2
 eureka.client.preferSameZoneEureka = true
 ```
 
+=== Refresh Scope of Eureka Client
+
+By default, the `EurekaClient` bean is refreshable, so the Eureka client properties can be refreshed, but this has a disadvantage:
+with the default setting, the `EurekaClient` instance will be destroyed and reconstructed again when refreshed, so your program will unregister from eurekaServer and after some seconds, it will register to eurekaServer again,
+consider that when we refresh all of the `Service A` instances at the same time, there will be some seconds no one instance alive on eurekaServer, if at the same time, `Service B` tries to fetch instances of `Service A`,
+it will fetch an empty list. If you don't want to see this, you can set `eureka.client.refresh.enable=false` in the application properties to make the `EurekaClient` instance immutable,
+but notice that if you set this property to false, none of the Eureka client properties will be refreshable.
+
+*application.properties. *
+```
+eureka.client.refresh.enable=false
+```
+
 [[spring-cloud-eureka-server]]
 == Service Discovery: Eureka Server
 

spring-cloud-netflix-eureka-client/src/main/resources/META-INF/additional-spring-configuration-metadata.json

@@ -9,7 +9,7 @@
     {
       "defaultValue": true,
       "name": "eureka.client.refresh.enable",
-      "description": "Determines whether EurekaClient instance can be refreshed or not.",
+      "description": "Determines whether the EurekaClient instance can be refreshed or not(If disabled none of the Eureka client properties will be refreshable).",
       "type": "java.lang.Boolean"
     },
     {