Drupal - Is there any compatibility issue with Amazon Aurora?

We are running a couple of projects on Amazon Aurora with no issues so far. Our largest project is a D7 project with many contributed modules, and a large amount of data being moved.

We've never noticed any DB related issues aside from normal MySQLisms. It's really transparent to Drupal. We use normal Mysql connection strings and zero core changes.

Aurora is more expensive. A lot more expensive. It only starts at the db.r3.large tier, and works out to a monthly (non upfront rate of 0.190 per hour). So the price difference must be considered.

Aurora isn't widely used in the community, but all the materials I've seen say it works (like this post).

To test a setup using AWS you could use the test drives setup by Acquia. I'm not sure if they are running Aurora on those or not, but it is probably worth a look.

As for testing custom modules there is a degree to which you cannot know until you either check a module and test it out, but most Drupal 7 contrib modules make use of Drupal's internal query APIs and therefore should not present issues on Aurora.