What is the benefit of having multiple databases in the same Availability Group vs single AG per database
We are planning a migration from current mirroring architecture to Availability Groups for several databases. For every Database we have defined the primary/secondary replica configuration.
The question that I'm unsure is: do we need to group the databases with the same primary/secondary configuration into the same AG, or use one AG per Database. What are pros&cons of having individual AGs vs AG with multiple databases? Is there a best practice to determine if a database needs its own AG or can be combined with others? Any performance or failover advantages?