I have a web application that consists of a web server managed by a web hosting firm, a set of EC2 instances in amazons cloud and a MySQL database (hosted on the webserver). MySQL is behind a firewall and is set to allow access from Localhost and from a single IP address which is an Amazon Elastic IP address that is attached to the EC2 instance I have been running up to now.

The problem is that I want to look at my scaling up and load balancing strategy for my EC2 instance. To this end I have been investigating the Elastic Load Balancers and Autoscaling tools that Amazon provides and have managed to set this up fine but for one thing - connecting to the MySQL database running on my webserver. I realised (thanks to answers on Serverfault) that I needed to check firewall settings and add the IP address for the load balancer, however Elastic Load Balancers provide you with a DNS name, not an IP address and infact the IP addresses change over time so this will not work. I have been told by the company hosting the database that the way the firewall works is to look up the IP address of the DNS name and store the IP rather than the DNS name. so basically this will not work and the only way to allow access would be to open up the SQL port to allow access from anyone!

Is this a viable idea? Should I look at moving my database into the cloud? Is there another firewall that the server company can use? Should I find another way of load balancing (if so what?)

tricky one eh? any help appreciated!