Update automate-update-messaging-units.md

Author: EldertGrootenboer

articles/service-bus-messaging/automate-update-messaging-units.md

@@ -55,7 +55,7 @@ You can configure automatic scaling of messaging units by using conditions. This
 You can't set a schedule to autoscale on a specific days or date range for a default condition. This scale condition is executed when none of the other scale conditions with schedules match. 
 
 > [!NOTE]
-> To improve the receive throughput, Service Bus keeps some messages in its cache. Service Bus trims the cache only when memory usage exceeds a certain high threshold like 90%. So if an entity is sending messages but not receiving them, those messages are cached and it reflects in increased memory usage. There is nothing to concern about, as Service Bus trims the cache if needed, which eventually causes the memory usage to go down. Memory will not cause any issue unless there is performance or any other issues with the namespace. We recommend that you use the CPU usage metric for autoscaling with Service Bus. 
+> To improve the receive throughput, Service Bus keeps some messages in its cache. Service Bus trims the cache only when memory usage exceeds a certain high threshold like 80%. So if an entity is sending messages but not receiving them, those messages are cached and it reflects in increased memory usage. Normally this means there is nothing to concern about, as Service Bus trims the cache if needed, which eventually causes the memory usage to go down. As such, it is recommended to only scale up once memory usage reaches 90%. Additionally, it is recommended not to scale down as long as memory usage does not go below 90%.
 
 ### Scale based on a metric
 The following procedure shows you how to add a condition to automatically increase messaging units (scale out) when the CPU usage is greater than 75% and decrease messaging units (scale in) when the CPU usage is less than 25%. Increments are done from 1 to 2, 2 to 4, 4 to 8, and 8 to 16. Similarly, decrements are done from 16 to 8, 8 to 4, 4 to 2, and 2 to 1.