Choose your own cloud adventure: the SaaS alternate ending
July 7, 2013
Grazed from Internap. Author: Andrew Boring.
In our previous post, we described IaaS (Infrastructure as a Service) and PaaS (Platform as a Service). Today we’ll discuss how Software as a Service (SaaS) fits into the stack and explore which type of infrastructure makes sense in different scenarios. Various combinations of these services can help meet your needs for flexibility and resource control so you can manage and create applications as desired.
SaaS
Most SaaS providers deliver end-user applications on-demand, as a service, over the Internet. Salesforce.com and Google Apps are two common examples of this. However, many SaaS applications can provide services to other applications, usually via a SOAP or RESTful API over the Internet. A good example of this is how Yelp integrates Google Maps into its mobile application – Google is the SaaS provider, and the Yelp application becomes the consumer of the software service…
A SaaS provider may use a PaaS provider or an IaaS provider, depending on the level of development and operational efforts they need to balance out. Here’s an illustration of how an application may interact with another SaaS provider:
As you can see, the application now interacts with other applications for complete functionality. Just as a developer can increase speed-to-launch by using a PaaS provider (at the expense of flexibility and customization), this developer can use existing third-party SaaS applications without having to recreate each piece of functionality desired.
Ultimately, the more you move your application “up the stack”, the fewer resources you are required to manage. Integrating an application with SaaS providers allows a developer to consume SaaS services as components and building blocks without having to reinvent the wheel (e.g., using Google Maps for location services, using RSS aggregators for content/news services, etc.)…
Read more from the source @ http://www.internap.com/2013/07/03/choose-your-own-cloud-adventure-the-saas-alternate-ending/