ANothere fix

Author: anantshankar17

articles/service-fabric/service-fabric-application-upgrade-advanced.md

@@ -17,7 +17,7 @@ Similarly, service types can be removed from an application as part of an upgrad
 
 For planned stateless instance downtimes, such as application/cluster upgrade or node deactivation, connections can get dropped due to the exposed endpoint is removed after the instance goes down, which results in forced connection closures.
 
-To avoid this, configure the *RequestDrain* (preview) feature by adding an *instance close delay duration* in the service configuration. This ensures that the endpoint advertised by the stateless instance is removed *before* the delay starts prior to closing the instance. This delay enables existing requests to drain gracefully before the instance actually goes down. Clients are notified of the endpoint change by a callback function at the time of starting the delay, so that they can re-resolve the endpoint and avoid sending new requests to the instance which is going down.
+To avoid this, configure the *RequestDrain* (preview) feature by adding an *instance close delay duration* in the service configuration to allow drain while receiving requests from other services within the cluster and are using Reverse Proxy or using resolve API with notification model for updating endpoints. This ensures that the endpoint advertised by the stateless instance is removed *before* the delay starts prior to closing the instance. This delay enables existing requests to drain gracefully before the instance actually goes down. Clients are notified of the endpoint change by a callback function at the time of starting the delay, so that they can re-resolve the endpoint and avoid sending new requests to the instance which is going down.
 
 ### Service configuration