Instance Limits are the most frequent one that can cause issues with CloudyCluster. In addition to instance limits, there are also limits on: VPCs, Subnets, Security Groups, VPC Peering Connections, etc… A complete list can be found here

What You Should Know Prior to starting your CloudyCluster setup, you should know the basic requirements for your HPC tasks. The size of your job and your desired time to results will determine the types of resources needed to run your job. If you don’t know the resources required, you can start with one of the CloudyCluster Quick Start configurations and try it out to get a feel for what you need to complete your job within your desired time frame.

Getting Started includes the following topics:

EC2 Key Pairs Launching the Initial Control Instance