Difference between Scale up and Scale out App Service plan

Question

Actually I am getting System.OutOfMemoryException for blob trigger azure function.Do i need to scale up or Scale out App Service Plan to fix this problem.

What is the difference between these two?

Answer 1

For your original question, if your function is running on consumption plan, Scale up App Service Plan of your Azure service.The plan you already have less Memory and if you have multiple functions running in App Service Plan then scale out.

From the docs,

Scale up means :

A scale up operation is the Azure Web Sites cloud equivalent of moving your non-cloud web site to a bigger physical server. So, scale up operations are useful to consider when your site is hitting a quota, signaling that you are outgrowing your existing mode or options. In addition, scaling up can be done on virtually any site without worrying about the implications of multi-instances data consistency. Two examples of scale up operations in Windows Azure Web Sites are:

Scale Out means:

A scale out operation is the equivalent of creating multiple copies of your web site and adding a load balancer to distribute the demand between them. When you scale out a web site in Windows Azure Web Sites there is no need to configure load balancing separately since this is already provided by the platform.

Digram depicting the difference between the two :