Yes, it's pretty easy to set this up with security groups, you can restrict ports to only open to machines within another security group. So lets say you've go

Yes, it's pretty easy to set this up with security groups, you can restrict ports to only open to machines within another security group. So lets say you've got memcached, mysql and a bunch of webservers. On the memcached security group you open 11211 to the webservers group On the db security group you open 3306 to webservers On the webserver group you open 80 and 443 to everyone.