I have deployed my model to a production Azure Kubernetes Service with 6 nodes.
Sequential inference requests get the expected response from score.py.
When I more than one concurrent async inference requests all the requests except for the first return 503 Too many requests for service {my service name} (overloaded).
I built my service and deployed my model based on the example @ https://github.com/Azure/MachineLearningNotebooks/blob/master/how-to-use-azureml/deployment/production-deploy-to-aks/production-deploy-to-aks.ipynb.
I am sending requests as large as 4mb. It seems to work when I send trivially small requests.