AWS EC2 and build-essential
build-essential is a package that resides in aptitude (Debian), not in Yum (RHEL). Maybe you should rephrase your question to provide more information about the core issue--i.e., installing EC2 tools?
The (rough) equivalent of the build-essential meta-package for yum is:
yum install make glibc-devel gcc patch
I'm assuming that you are building node.js, as I had the same problem. I think the one you are missing is:
yum install gcc-c++
But you might need more than that one after you get past the first part.