PaaS-Reference Architecture

Dear Software Vendors,

I’d like to point you to an short but excellent blog post of Roman Stanek, entrepreneur and currently founder and CEO of the SaaS BI vendor Gooddata:

Back in the old good days … We delivered bits on DVDs… Throwing software over the wall … that’s how we did it. Sometimes almost literally…

I now live in the SaaS world….… But there now seems to be a new way how to “throw software over the wall” again. Many software companies have repackaged their software as Amazon Machine Image (AMI) and relabeled them as SaaS or Cloud Computing.

There is obviously some value in offering prepackaged images, eg. for pre-integrated middleware stacks into development and test clouds. This is what IBM and others are offering. However if a software vendor simply takes a traditional software package, boils it down into an EC2 image and let the customer alone with it, we lost one of the most important accomplishments of the SaaS deployment approach. That’s what Roman’s words of caution are all about and I couldn’t agree more.

The EC2 image is a one time snapshot, like a DVD in old days. However, the real SaaS business application or a Platform as a Service (PaaS) is a consistently and ongoing maintained software availability – not a one time deployment.

Customers should therefore be very careful if vendors are simply talking about a cloud deployment. Ask for the real value and ongoing services. It looks like that a multi tenant stack like can be maintained easier in many cases that a deployment of a single image per tenant, multiplied for thousands of tenants into an hypervised environment. Companies like vmware are heavily investing now to avoid the IT management overkill in such environments. Also IBM is aware of the challenge similar to vmware and enables their WebSphere cloudburst appliance to deal even with incremental changes in hypervisor images, while they are still missing to enable a multi tenancy on the higher level of their middleware stack.

That’s the reason why PaaS and SaaS goes much beyond of the value of an “simple” infrastructure as a service “IaaS”.