Azure API Management Scalability

Question

Azure API Management has promises of 1000 requests per second for an instance. (I don't know this is a correct rate but let's assume it is). My question is how can we scale web service without scaling its infrastructure just by scaling API Management instance.

For example if Azure API Management supports 1000 requests per second for an instance, then backend service also should support the same request handling threshold in its infrastructure. If this is the case what is really meant by scaling up the web service by Azure API Management.

Answer 1

By using Azure API management you can turn on caching easily, which can significantly reduce the traffic to your back-end. In addition, your API Management instance can be scaled up easily to have more VMs behind it. However, if the back-end cannot handle the traffic (after caching), then you might need a more scalable back-end :)

Answer 2

Miao is correct. However remember Azure API Management scaling will only work with GET request. Plus cache size provided by API Management is of only 1GBas of today [may increase in future]; with no monitoring as of today. So if you need monitoring of API Management cache then use external cache like Redis. When you talk about scalability it will be at all layers. API Management consumption plan can be good option to think through for auto scaling. Then think of Azure VMSS or App service auto scale for scaling backed APIs. And if your backend APIS are talking to DB then think of something like Autoscale for DB on Azure like SQL Azure HyperScale. So scalability is not only at API Management level but think carefully at all layers.

Sample implementation of Cache in API Management is here - https://sanganakauthority.blogspot.com/2019/09/improve-azure-api-management.html