I am setting up load balancing for my Amazon RDS Read Replicas using HAProxy, should I use a m1.large or c1.medium instance type for running HAProxy ?
thanks
You might want to look into Elasticache.
If you are determined to use HAProxy then I'd select the instance with a higher memory level when load balancing read replicas.
Are you going to run a cluster of HAProxy so that this is not a single point of failure?