Azure: share resource across multiple resource group

Question

Is it possible to share a particular resource (redis cache in my case) across multiple resource group?

Answer 1

Resource group is just logical container. It doesn't matter in which resource group resource is. You can use resources from any resource group.

Example:
Imagine that you create App Service Plan in RG1 and Web App Service in RG2. This Web App Service can use App Service Plan from RG1.