updates

Author: EdB-MSFT

articles/azure-monitor/essentials/create-diagnostic-settings.md

@@ -222,6 +222,15 @@ Diagnostic settings don't support resource IDs with non-ASCII characters. For ex
 
 Every effort is made to ensure all log data is sent correctly to your destinations, however it's not possible to guarantee 100% data transfer of logs between endpoints. Retries and other mechanisms are in place to work around these issues and attempt to ensure log data arrives at the endpoint.
 
+### Inactive resources
+
+When a resource is inactive and exporting zero-value metrics, the diagnostic setting export mechanism back off incrementally to avoid unnecessary costs of exporting and storing zero values. The back-off may lead to a delay in the export of the next non-zero value. 
+
+When a resource is inactive for one hour, the export mechanism backs off to 15 minutes. This means that there is a potential latency of up to 15 minutes for the next nonzero value to be exported. The maximum backoff time of two hours is reached after seven days of inactivity. Once the resource starts exporting nonzero values, the export mechanism reverts to the original export latency of three minutes. 
+
+This behavior only applies to exported metrics and doesn't affect metrics-based alerts or autosacle.
+
+
 ## Next steps
 
 - [Review how to work with diagnostic settings in Azure Monitor](./diagnostic-settings.md)