I am currently hosting my database inside a t2.large instance on AWS EC2 which provides 8GB RAM and 2 CPUs. I am now looking for better options which are more scalable and provides features like master-slave replication, automatic backups, etc.
I have found AWS RDS Multi A-Z and DigitalOcean Managed Databases to be quite similar in what they offer however the pricing is quite different. Any suggestions on which one to prefer? Are there any other reasonable options? My requirements are 32GB RAM and 500GB of disk space which should be expandable without any downtime.
Also any disadvantages of using AWS RDS Reserved Instance over On-demand instance? Can one increase disk space and RAM in Reserved Instance without any downtime?