PaaS fits in the middle of the cloud-computing stack, between SaaS on top and IaaS at the bottom.
“SaaS simply refers to software that is provided on-demand for use,” notes the author, Michael P. McGrath, a founding member of Red Hat’s OpenShift and currently its “Principal Cloud Architect.” He also is operations manager for all of Red Hat’s PaaS offerings. “There’s no magic to it [SaaS],” he adds. For example: “Anyone who has used web mail of any kind has been using SaaS.”
Meanwhile: “Proper IaaS provides a mechanism for people to replace all of their data center hardware needs.” The infrastructure services that can be obtained from the cloud include: host provisioning, load balancing, public and private network connectivity, firewalls, and storage.
“Additionally, all of the dependencies for these services also are provided” by IaaS providers, the author points out.
“PaaS providers offer a platform for others to use,” he adds. “What is being provided is part operating system and part middleware. A proper PaaS provider takes care of everything needed to run some specific language or technology stack.” And: “PaaS today focuses almost entirely on web solutions. The components an end user interacts with are all web-based and because of this, most PaaS providers excel when it comes to large numbers of short lived process requests.”
McGrath’s book is divided into six short chapters:
1. What is Cloud Computing? – Describes the three levels and shows how to set up a virtual machine via Amazon Web Services’ Elastic Compute Cloud (EC2).
2. Why PaaS? - “PaaS provides a carefree environment for developers to work….By utilizing PaaS, developers simply pick the languages and features they want, match those requirements with a provider that has them, and start coding.” Discusses common features, costs and maintenance.
3. What to Expect - “PaaS makes it so easy to run code remotely that options are now available to do all development in the cloud.” Discusses why “a pre-built application may not automatically work when uploaded to PaaS.” Looks at tools, providers, development workflow and automated testing.
4. Examples - Provide code for creating a sample application using Red Hat’s OpenShift platform.
5. Architecture – Focuses on the “three primary concerns when dealing with networking in the cloud”: connectivity, bandwidth and latency.
6. Summary - McGrath says PaaS offers many solutions and now is “an exciting time for cloud providers. Go out, try some, and see how they can make IT easier and once again, enjoyable.”
If you are curious about cloud computing or ready now to try some development in the cloud, add this well-focused little book to your reading list and reference library.
– Si Dunn is a novelist, screenwriter, freelance book reviewer, and former software technical writer and software/hardware QA test specialist. His latest book is a detective novel, Erwin’s Law. His other published works include Jump, a novella, and a book of poetry, plus several short stories, including The 7th Mars Cavalry, all available on Kindle.