I run a site which has high traffic surges and because of that auto scaling solutions is very profitable for this case. Currently the web server is able to horizontally auto scale but the bottleneck is on the MySQL server.
- I have tried with Amazon RDS Multi-AZ but it takes like 15 minutes for the 12 GB database to upgrade with some minutes of downtime. It has helped a lot when I already knew that a traffic surge was going to happen in some specific moment.
- I have also considered Xeround. This is probably the best solution although it is quite expensive for databases of this size. Anyway it is not an option because I legally need the database to be in the European Union.
- I have read about Scalr but not sure if that could be helpful and how.
- I have seen that many cloud hosting providers offer vertical scaling solutions which I think it has 0 downtime (not sure if that is really possible, as far as I know they use Xen hypervisor). That could be a solution but I wonder if it has not downtime and how the MySQL config (and many other things on the OS) are able to upgrade also without downtime.
- I have tried with MySQL slave servers but it was not helpful at all.
- I am using memcache which helps a lot but it is not enough. I need to upgrade because of writes, not just because of reads.
Any suggestions? Thank you in advance