Can traditional IT infrastructure (high-performance firewalls, load balancers, and switches) be married to a server cloud?  Based on my experience, the answer is “yes” but it ain’t easy.

You might ask why someone would want to do that when there are cheap public alternatives like Amazon AWS or RackspaceCloud.  There are a couple of good reasons.  First, there can be legal or privacy reasons why a company would want to carefully control where servers and data reside.  Second, you can get more robust performance by using hardware firewalls and load balancers.

One way to implement a private cloud like this would be to use the Eucalyptus open source code, which allows you to build a private cloud that mimics Amazon EC2.  That’s not a bad approach for some types of applications.  But it doesn’t leverage those high-performance firewalls and load balancers.

So what are the requirements for creating a private cloud that can be married to IT infrastructure?  Here are the functions that need to happen:

• If it’s a new pool of servers, set up the firewall, load balancer, and switches for the new pool.
• Spawn or destroy virtual servers.
• Add the IP addresses for those virtual servers to a switch.
• Add the IP addresses to a load balancer pool and apply the proper health monitors.
• Add the IP addresses to monitoring software (e.g. nagios, SiteScope, etc.) to get alerts if something should go wrong.
• If you need elasticity, be able to monitor pertinent metrics such as CPU load or disk usage, and then use control system theory to increase or decrease the number of virtual servers over time.
• This all has to be under software control, so everything that needs to happen automatically needs some sort of API to make it happen.

As far as I know, there are no commercial solutions that handle all of these things today, so that means you’d have to roll your own software to do it.  It’s certainly all quite possible to do, but it ain’t easy.

This entry was posted on Thursday, April 22nd, 2010 at 8:56 am and is filed under Cloud Computing . You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.