Do we need another as-a-service to describe functions?

Posted on By Mark Wilson
This content is 8 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

Last week saw quarterly earnings reports for major cloud vendors and this tweet caught my eye:

You see, despite Azure growing by 93%, this suggests that Amazon has the cloud market sewn up. Except I’m not sure they do…

I think it would be interesting to see this separated into infrastructure-, platform- and software-as-a-service (IaaS/PaaS/SaaS). I suggest that would present three very different stories. And I’d expect that Amazon would only really be way out front for IaaS.

My friend and former colleague, Garry Martin (@GarryMartin) questioned the relevance of those “legacy” distinctions but I think they still have value today.

In the early days of what we now recognise as cloud computing, every vendor was applying their own brand of cloud-washing. It still happens today, with vendors claiming to offer IaaS when really they have a hosted service and a traditional delivery model.

Back in 2011, the US National Institute of Standards and Technology (NIST) defined cloud computing, including the service models of IaaS, PaaS and SaaS. Those service models, along with the (also abused) deployment models (public cloud, private cloud, etc.) have served us well but are they really legacy?

I don’t think they are. Six years is a long time in IT, let alone the cloud but I think IaaS, PaaS and SaaS are as relevant today as they were when NIST wrote their definition.

When asked how “serverless” technologies like AWS Lambda, Azure Functions or Google Cloud Functions fit in, I say they’re just PaaS. Done right.

Some people want to add another service model/definition for Function-as-a-Service (FaaS). But why? What value does it add? Functions are just PaaS but we’ve finally evolved to a place where we are moving past the point of caring about what the code runs on and letting the cloud manage that for us. That’s what PaaS has supposed to have been doing for years (after all, should I really need to define a number of instances to run my web application – that all sounds a bit like virtual machines to me…)

To my mind, “serverless” is just the ultimate platform as a service and we really don’t need another service model to describe it.

To quote a haiku from Onsi Fakhouri (@onsijoe):

“Here is my code
Run it in the cloud for me
I don’t care how”

Or, as Simon Wardley (@swardley) “fixed” this Cloud Foundry diagram:

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