Websockets update

Author: jaesoni

articles/application-gateway/configuration-http-settings.md

@@ -5,7 +5,7 @@ services: application-gateway
 author: greg-lindsay
 ms.service: application-gateway
 ms.topic: conceptual
-ms.date: 09/13/2022
+ms.date: 03/17/2023
 ms.author: greglin
 ---
 
@@ -34,7 +34,12 @@ Please refer to TLS offload and End-to-End TLS documentation for Application Gat
 
 ## Connection draining
 
-Connection draining helps you gracefully remove backend pool members during planned service updates. It applies to backend instances that are explicitly removed from the backend pool or during scale-in of backend instances. You can apply this setting to all members of a backend pool by enabling connection draining on the Backend Setting. It ensures that all deregistering instances of a backend pool continue to maintain existing connections and serve on-going requests for a configurable timeout and don't receive any new requests or connections. 
+Connection draining helps you gracefully remove backend pool members during planned service updates. It applies to backend instances that are 
+- explicitly removed from the backend pool,
+- removed during scale-in operations, or
+- reported as unhealthy by the health probes.
+
+You can apply this setting to all backend pool members by enabling Connection Draining in the Backend Setting. It ensures that all deregistering instances of a backend pool continue to maintain existing connections, to serve the ongoing requests until the configured timeout value, and don't receive any new requests or connections. This is true for WebSocket connections also.
 
 | Configuration Type  | Value |
 | ---------- | ---------- |