Surprised to see AWS Aurora *slower* than RDS

We migrated from MySQL RDS/AZ to Aurora and a number of our queries became ~22% slower.

Old DB: t2.medium RDS AZ

New DB: Aurora r3.large

For example, a representative set of SELECT queries run against both DBs:

$ time rds-db real 0m34.502s

$ time aurora-db real 0m42.240s

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We got a reply from AWS support person who contacted Aurora Tech team on our behalf. I include his reply, relevant if you're seeing similar degradation of performance. In a nutshell, single queries are _expected_ to be slower on Aurora. Aurora will scale better with concurrency.

"Nice talking on the phone with you! I have talked to RDS team about your issue with performance after switching to RDS Aurora.

The RDS team pointed out that Aurora’s performance will not be better than MySQL if the concurrency features are not used or if you are using Aurora as a traditional MySQL. They said Aurora will be highly beneficial if your work load is highly concurrent.

Aurora though should have 5x more throughput than RDS MySQL but only when the work load is used efficiently as it works well with multiple concurrent queries."

This will apply to a lot of technologies - of course X is slower than Y if you don't optimise your app to take advantage of the features and architecture of X.

What that means in terms of RDS vs Aurora, I'm not sure. But would be great to hear what your outcomes are!