- review BUG related doc for Health and Premotheus after change of behavior to...

- review BUG related doc for Health and Premotheus after change of behavior to be compatible with reload feature. (#1790)

plugin/health/README.md

@@ -93,3 +93,10 @@ Set a lameduck duration of 1 second:
     }
 }
 ~~~
+
+## Bugs
+
+When reloading, the Health handler is stopped before the new server instance is started. 
+If that new server fails to start, then the initial server instance is still available and DNS queries still served, 
+but Health handler stays down. 
+Health will not reply HTTP request until a successful reload or a complete restart of CoreDNS.

plugin/metrics/README.md

@@ -71,5 +71,7 @@ then:
 
 ## Bugs
 
-When reloading, we keep the handler running, meaning that any changes to the handler's address
-aren't picked up. You'll need to restart CoreDNS for that to happen.
+When reloading, the Prometheus handler is stopped before the new server instance is started. 
+If that new server fails to start, then the initial server instance is still available and DNS queries still served, 
+but Prometheus handler stays down. 
+Prometheus will not reply HTTP request until a successful reload or a complete restart of CoreDNS.