Serverless is generally a non starter unless you have a really really spikey workload
For Aurora in general, here’s a short list:
* Since the storage is separated, and farther than even EBS, latency is worse. Local, on-hardware NVMe is blindingly fast, enough that you can often forget that it isn’t RAM.
* I’ve yet to see Aurora perform better; MySQL or Postgres variants. My 13 year old Dell R620s literally outperform them; I’ve tested it.
* The claimed benefit of being able to take a DB up to 128 TiB is a. an artificial limit that they’ve made worse by denying the same to RDS b. difficult to reach in practice, because of a bunch of gotchas like fixed-size temporary storage, which can make it impossible to do online DDL of large tables.
* For the MySQL variant, they removed the change buffer entirely (since storage is distributed, it was necessary for their design), which dramatically slows down writes to tables with secondary indices.
* It’s not open-source. I can and have pored through Postgres and MySQL source code, built debug builds, etc. to figure out why something was happening.
I don't know much about the MySQL variant.
Aurora isn't open source but I'm also not sure there's a compelling reason. It's highly reliant on AWS ability to run massive scale storage systems that amortize the IO cost across tons of physical devices (their proprietary SAN).
If you have dedicated staff, managed services are definitely less compelling. We have 2 infrastructure engineers to run 15+ platforms so we're definitely getting a lot of leverage out of managed services. We'd have to 5x in size/cost to justify a specialist.