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  • AWS docs
  • Google Cloud Platform docs

    There is no official information on read replica limit - this was based on tests

  • Azure docs

Additional facts

  • On both AWS and GCP you can configure HA option - in case of AWS RDS it is fully transparent (you cannot see the instance itself) and synchronous while on GCP it is semisynchronous and the failover instance is visible and manageable
  • GCP additionally is able to replicate to and from externally hosted MySQL instances
  • At the time of publication of this fact, MySQL on Azure was still in preview and didn’t have read replication options


  • When your app uses MySQL and you need to scale reads then GCP has the best offer when it comes to flexibility
  • If you’re cautious and need to provide higher level of availability then multi-region offered by AWS RDS might be the best option
  • Apparently when you use Azure you use Microsoft SQL Server rather than MySQL - it’s not the best platform for apps using this db engine

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