What's the diffrence between IaaS and PaaS

JaneDoe

I don't understand the difference between Infrastructure as a Service (IaaS) and Platform as a Service (PaaS). Is IaaS renting a dedicated server while PaaS is renting a Virtual Machine? Is IaaS unmanned hosting while PaaS is managed hosting? The book lists EC2 as an example of PaaS, but EC2 is really just renting a virtual server with some pre-configurations. Is there a clear technical line between IaaS and PaaS or the difference just the providers marketing?

kj0

I haven't looked into AWS, but Eli explains them all very well in his Virtual/Cloud computing sessions. You can check them all out here. He even cover MaaS.

Cloud and Virtual Computing - YouTube

dpsmooth15

I am not getting paid commission for this, but I would suggest paying $20.67 (amazon) for the Security+ book Mr. Gibson has. Iaas, Paas, and Saas are on the Security+ exam. (I seen it with my own eyes ). And you need "specific/detailed" answers in reference to those three… a broad cloud computing will not help you per say and Security+ is not a cloud exam, . having 15 people give you the same answer 15 different ways will only confuse you. I would SOLELY work on understanding IaaS Paas and Saas, in reference to cloud computing.

ThePawofRizzo

PaaS is Platform as a Service, and generally would be a specific development platform for application developers (programmers). Infrastructure as a Service would include virtual servers, networks, and storage, not a development platform, per se.

Rackspace has a Cloud University of 10 lessons on cloud computing that you may find helpful. There are short quizzes after the brief readings to assess if you're learning the material. Really, you could probably knock out the lessons in a few hours, and gain some good basics about PaaS, IaaS, and SaaS.

JaneDoe

The explanation in Gibsons book is confusing me more that's why I asked here. I understand the difference between SaaS and IaaS perfectly. A virtual development environment is something you can run on a virtual server if you choice to do so. Am I to understand that if I spin up an EC2 instance and host a web sever on it, that's IaaS once it's in production, but PaaS before it goes into production, while I'm building the web site? Which is it while I'm configuring the server?

JaneDoe

kj0, thanks for the video, I get it now. PaaS = Shared Hosting, and similar shared services, where resources are not dedicated to any one client as they are in IaaS. I was confused because the example in Gibsons book is wrong, or at least a borderline case - EC2 is IaaS not PaaS.

Darril

One thing about cloud-based services is that they are growing, and as with many other topics in the Security+ exam, cloud topics have a lot more depth. Digging deeper can certainly help you get a deeper understanding, and I applaud your efforts to get a full understanding.

JaneDoe wrote: »

PaaS = Shared Hosting, and similar shared services, where resources are not dedicated to any one client as they are in IaaS.

I'm not sure that is an accurate description. Here are two basic distinctions between IaaS and PaaS

• With IaaS, you're given access to hardware resources which you must configure yourself.
• With PaaS, you're given access to preconfigured resources which you can manipulate.

Imagine you need to buy a computer to develop PHP applications on a Linux operating system and you have the following two options.

1) One computer comes without an operating system (or comes with Windows but you need Linux).

• The hardware will work, but you'll need to do all the configuration yourself.
• This is probably cheaper but it will take you a lot longer to configure the system so that you can start your development work.
• With this computer, you cannot expect the seller to install the operating system and configure it. This is your responsibility.

2) The second computer comes with Linux installed, and all the developer components required to develop and test PHP applications.

• This computer works out of the box.
• This might be more expensive, but you can just plug it in and start developing.
• If the computer does not have the promised operating system or developer components, you can take it back to the seller to resolve the problem.

These same two options are available via cloud-based services.

1) IaaS. Access to computing resources without the required operating system and developer resources.
The IaaS provider is not responsible for any configuration of this computer.

2) Paas. Access to computing resources with a preconfigured platform.
The PaaS provider is responsible for configuration of the computer based on the platform they provide. More, many PaaS providers also provide maintenance services for the platforms such as updates.

This page (https://www.engineyard.com/paas-vs-iaas) compares the two from the perspective of a company that calls itself a PaaS provider dedicated to providing platforms for developers. I like their graphic showing what is vendor-managed, and what is customer-managed for IaaS, PaaS, and SaaS.

Companies that sell both IaaS and PaaS services can sell them as dedicated servers or shared servers. A dedicated server is a dedicated piece of hardware with all of the computing resources used by the customer paying for it. A shared server can have have multiple virtual instances (or virtual machines VMs), with multiple customers paying for their individual instances or VMs.

It's also possible for a company to sell access to shared services or shared hosting off a single server. For example, a web hosting provider can configure a single server as a web server and then sell access to this server to 100 customers. While this can be called PaaS, all instances of PaaS are not sold as shared hosting or shared services. Engineyard is one of many examples.

JaneDoe wrote: »

Am I to understand that if I spin up an EC2 instance and host a web sever on it, that's IaaS once it's in production, but PaaS before it goes into production, while I'm building the web site? Which is it while I'm configuring the server?

The service provided by the company doesn't change, and their responsibilities do not change. They rent you access to either the infrastructure (hardware) as an IaaS provider, or they rent you access to the infrastructure with a preconfigured platform.
If you rent an IaaS service, they will not assume responsibility of the platform after you've configured it.

JaneDoe wrote: »

I was confused because the example in Gibsons book is wrong, or at least a borderline case - EC2 is IaaS not PaaS.

I'm not sure what makes you think that Amazon's EC2 is IaaS not PaaS. This page explains how they provide preconfigured images with full operating systems. What is Amazon EC2? - Amazon Elastic Compute Cloud. They do have different platforms than other providers such as EngineYard, and the platforms between any two companies are likely to be different based on their target audience. However, the key here is that Amazon provides the preconfigured platform.

You might notice that unlike EngineYard, Amazon doesn't label their services as either IaaS or PaaS. They actually have multiple options that they sell and if customers want to purchase access to systems, but completely reconfigure them and take full responsibility for the platforms, they can. Technically, that is IaaS. However, from a customer's point of view, terms such as IaaS and PaaS are confusing. Shoot, they can be confusing to just about anyone new to cloud-based computing. The shorter message from Amazon is you can get what you want.

Hope this helps.

"My other computer is a cloud."

JaneDoe

Darril wrote: »

I'm not sure what makes you think that Amazon's EC2 is IaaS not PaaS. This page explains how they provide preconfigured images with full operating systems.

I've worked with Amazon EC2, and I had to do all of the configuration myself. Amazon even allows you to upload your own OS images if you chose to do so. All VPS providers provide preconfigured images with full operating systems; if that alone make a system PaaS, then IaaS does not exist (unless it refers to something else, like renting a dedicated server). Some cloud providers do more pre-configuration than others, but that doesn't change the fundamental service.

There is a difference between managed and unmanaged hosting; in unmanaged hosting you have full administrative access while manged hosting leaves the provider in charge. Both types of hosting are used for development and production systems. It's best practice to use a development system that mirrors a production system as closely as possible, so I'm having trouble understanding the IaaS vs. PaaS in the context of development vs. production.

Am I still misunderstanding this concept? Is there a chart somewhere of characteristics of IaaS vs. PaaS systems?

jaywalker

I trashed my vca-cloud notes explaining the differences, but maybe this will help:

Quoted from Arstechnica:

Unlike IaaS, PaaS tends to be optimized for building and hosting applications without having to manage operating systems and virtual computing infrastructure.

Also, Rackspace's CloudU covers the PaaS/IaaS differences on video. Skip to 1:42 to jump right in.