VMTN Blog

John Sequiera ponders the question: "Why on-demand appliances?" He gets virtualization, but the 'resource pool' approach of something like Amazon's EC2 does require a shift in thinking and comfort level with IT as a utility. I think John's a-ha here is more about the usefulness of virtual appliances, whether they're in the cloud or in your ESX Server at the data center. I personally see the most need for on-demand computing around capacity management (unexpected DOS attacks or planned seasonal surges) and capital management (why buy when you can lease?).

Link: John Sequeira's Weblog.

Why is this cool? Well, consider the difference between your typical startup and a mature web enterprise: to really run a web hosted application according to best practices, you should have

 

• staging setup
• production setup,
  
• hot standby, DR plan
  
• version control repository/bug tracker
  
• integrated authentication
  
• distributed file system
  
• load balancer
  
• firewall/intrusion detection
  
• etc.
  

And no one does initially because it takes a lot of time, money and expertise to put all these pieces in place. But what if you could have it all initially and it didn't cost an arm and a leg? The idea of a vendor (like, say Novell or RH) pre-provisioning all the machines required to pull the above off, and offering them via the Amazon EC2 Control Panel is quite compelling. Imagine the options:

 

• Statefull Firewall with mod_security? Check. 
• Dedicated Image Server pre-configured with optional Akamai CDN support?  Check. 
  
• Web analytics reporting server? Check
  
• Offline bi/olap database with real-time replication? You get the idea.
  

Each check on that control panel is the equivalent of days or weeks of work on your hand-rolled data center.