Don’t let the cloud bite you in the PaaS

Analyst Gartner predicted recently that all leading enterprise software vendors and large cloud specialists will introduce new platform-as-a-service (PaaS) offerings this year. In fact, it termed 2011 “the year of PaaS”.

“By the end of 2011, the battle for leadership in PaaS and the key PaaS segments will spread throughout the software industry,” said Yefim Natis, vice president and distinguished analyst at Gartner.

But what is PaaS, and how does it compare with cloud sibling infrastructure-as-a-service (IaaS), a service that has also taken off in recent years? (It is generally considered that software-as-a-service or SaaS, the third part of the infrastructure, is now well established.)

Natis argued that the best way to describe PaaS is as “middleware-as-a-service”.

“It is the middle tier in cloud architecture. Below it is the systems infrastructure comprising virtual machines, operating systems, networking, storage – everything that hides the hardware. Above are business applications. That is, software designed to automate business processes. Everything between the business and
systems infrastructure is PaaS. It’s a very big space.”

PaaS therefore includes application servers, integration brokers (software that interconnects applications), databases and database management systems, where business data is stored.

“Anything that is not a business application or systems infrastructure is PaaS,”
said Natis.

But this definition of PaaS can be refined even further. Natis explained that aPaaS, or Application PaaS, is what most people understand by PaaS.

“Most of the time when people talk about PaaS they mean aPaaS. That is the part of PaaS that is responsible for hosting the top layer of the cloud – business applications.”

Business applications do not operate in a vacuum, they require a container or environment in which to run. Natis gives the on-premises, non-cloud examples of Oracle’s WebLogic, IBM’s WebSphere and the Microsoft.NET framework. These are all application servers, or containers, in which business applications exist.

In the cloud the situation is the same; there has to be a container in which the application runs. The difference is that the container must be also cloud-enabled.

“Current examples of aPaaS are Force.com from Salesforce.com, App Engine from Google, Windows Azure from Microsoft and VMforce, which will be released later this year by VMware.”

Although aPaaS is the most popular form of PaaS, it is not the only one currently available. There is also integration PaaS, or iPaaS. This is dedicated not to hosting applications, but to integrating and intermediating between applications.

“It’s the connecting tissue between different business services. It’s about interoperability, integration, intermediation and governance [with an underlying infrastructure],” said Natis.

Given that aPaaS has the biggest uptake of the two, who are the early adopters?
Natis explained that SMEs are the trailblazers, as they generally do not possess the financial capacity to run their own state-of-the-art IT departments with several operating environments. Given their restricted budgets, many SMEs feel that they are better served by the cloud.

But large organisations also use aPaaS in some circumstances, even if they have not yet embraced it as a mainstream service.

“They use it when they’re in a hurry, when they need to start and finish a project quickly. It saves time, they do not have to provision, buy, deploy, configure or integrate anything. They sign a contract with a provider, and start work the next day.”

So if increased flexibility and agility is the result, why is aPaaS not a given for the enterprise today? The answer, according to Natis, is one of trust.

“They don’t trust cloud providers to do as good a job as their own IT. They don’t trust providers in terms of security, performance, availability or even long-term viability.

“This adoption of aPaaS is most viable for short-term, compute-heavy projects such as software development. It does not make sense to buy 100 servers, which will be redundant in six months, when the project ends, so companies rent the resources in the cloud,” he said.

Natis said that PaaS as a whole is set to generate more revenue this year for its vendors.

“Very little money is so far generated in the middle tier but that will change. It doesn’t mean PaaS is unimportant, it just means that it is new.”