What are applications of alphabetic trees?

What is the best way to host multiple Independent Applications in a VPC?

• I have been trying to implement a network architecture for my needs and have come up short. The web hasn't presented a solution either: I have setup a VPC with a public and a private subnet (each a /24 subnet) I provide web applications to my customers through AWS, and since each customer is different, they'd have their own domain name so their app would be accessible as: http://app1.customer1.com http://app2.customer1.com . . . http://appN.customerN.com My intended use case is: Typing any of these addresses on a browser would route the user to the EC2 web server for the specific application and return the response. Ideally, each application would run on it's own web server, which should be internet accessible. Each web server will be on the public subnet. Each app will probably have a DB server, which will be on the private subnet. The first thing I though of was assign each web server an EIP address (I know, those don't grow on trees). So I read up of some alternatives, and all I find is people saying to either use a NAT or ask Amazon for more EIPs. NAT obviously will not work since it only allows nodes in my VPC to access the internet, and not the opposite. Asking for more EIPs is a no go, because I am trying to do this efficiently. I also read a lot about ELBs (I don't know a lot about load balancing), and from what I learned, this only works for a single application setup, in which all nodes under the ELB return the same response. Then there is Route53, which I thought would save my life. From what I read, It will basically map a domain name to an IP, so I thought of using it to map domain names to private IPs in my VPC. That turned out to be a no go because apparently Route53 does not work with IPs inside VPCs. What I am trying to achieve is illustrated in the image attachment I made. Additionally, I know that a VPC with two /24 subnets can only hold about 120 applications this way (if each app has 2 servers at most), since I will have a web server on the public and the db server on the private. How can I improve this architecture to allow for more hosted apps?

• Answer:

  So after some more research and asking around, here it is: Basically, I could setup several nginx web servers to direct traffic to each specific web server according to the incoming request. All nginx servers would be under an elastic load balancer, so I would only need one elastic IP to accomplish this, and the only component to reside on the public subnet would be the ELB. The problem would then be SSL, since currently no server can host different certificates for different domains under the same IP. SNI would have been a great solution, but since windows XP does not support it, i would cut off too many users (warnings are no good). The only solution is to really ask amazon to lift my EIP limits and use them responsibly. So I'm back at square one. Damn you XP.