Yes, this is definately possible and is one of the more popular ways to instrument auto-scaling
-
First, instrument monitoring of a particular queue or queues by monitoring the Azure resource that the queue is located in. Instrument monitoring of the AzureStorageQueueLength or the AzureServiceBusActiveMessageCount metrics within their particular resources.
-
Second, link the monitored metric to a particular monitored cloud service via LinkedMetric metric. This will import monitored data from one resource to another.
-
Third, instrument your scaling rules using the newly defined Linked metric.