What is Cloud Computing?
There are plenty of definitions for "cloud computing" online, and for the most part, they generally point to the same thing: taking applications and running them on infrastructure other than your own. Companies or individuals who offload or effectively "outsource" their hardware and/or applications are running those apps "in the cloud." Business applications are moving to the cloud. It’s not just a fad—the shift from traditional software models to the Internet has steadily gained momentum over the last 10 years. Looking ahead, the next decade of cloud computing promises new ways to collaborate everywhere, through mobile devices
While the advent of contemporary computer networking happened in the mid-1970s, no talk of anything remotely resembling a concept like "cloud computing" came about until about a decade later in 1984 when John Gage of Sun Microsystems coined the memorable slogan, "The network is the computer."
As prophetic as Sun was back in the day, hardware (primary compute and networking) was neither powerful nor commoditized enough to realize this vision at the time. Cloud computing was still at least a decade away. In the meantime, Sun's Unix-flavored operating system and servers became the "new iron," replacing mainframes that been around for several decades. And Sun became the “dot in dotcom” For the sake of transparency, we must express that we have been Sun’s Business partner since our inception.
Sun's machines used open networking standards such as TCP/IP. This enabled programs running on one machine to talk to running programs on other machines. Such applications generally followed the client-server architecture model.
Cloud computing: a better way
With cloud computing, you eliminate those headaches because you’re not managing hardware and software—that’s the responsibility of an experienced vendor like salesforce.com. The shared infrastructure means it works like a utility: You only pay for what you need, upgrades are automatic, and scaling up or down is easy. Cloud-based apps can be up and running in days or weeks, and they cost less. With a cloud app, you just open a browser, log in, customize the app, and start using it.
Businesses are running all kinds of apps in the cloud, like customer relationship management (CRM), HR, accounting, and much more. Some of the world’s largest companies moved their applications to the cloud with salesforce.com after rigorously testing the security and reliability of our infrastructure.
As cloud computing grows in popularity, thousands of companies are simply rebranding their non-cloud products and services as “cloud computing.” Always dig deeper when evaluating cloud offerings and keep in mind that if you have to buy and manage hardware and software, what you’re looking at isn’t really cloud computing but a false cloud.
Cloud Computing Service Levels
In the figure to the right, you can see how the analyst firm Gartner segregates cloud computing.
These classes map directly from the different types of cloud service described at the end of the previous subsection. Let's explore these in detail here.
Software as a Service (SaaS)
Let's start at the highest level: software applications that are only available online fall into the "Software-as-a-Service" category, also known as "SaaS". The simplest example to understand is e-mail.
If you have an Internet provider, you'll need a desktop or mobile application to access that e-mail, else host it on your own servers. Not only would you have to run an inbound mail server using protocols such as IMAP (or POP for older systems), but you would also need to run an SMTP or outbound mail server. Then you'd have to configure your desktop or mobile e-mail application to connect to those servers, add appropriate levels of security, quota management, etc.
For personal e-mail, people typically select from a variety of free web-based e-mail servers such as Google's Gmail, Yahoo!Mail, or Microsoft's Hotmail, rather than setting up all of the above through their provider. Not only is it "free" (supported through advertising), but users are freed from any additional server maintenance. Another example of SaaS from Google includes their Apps product: office productivity software hosted and run by Google online.
Because these applications run (and store their online), users no longer need to worry about managing, saving, and backing up their files. Of course, now it becomes Google's responsibility to ensure that your data is safe and secure . Other examples of SaaS include Salesforce, IBM's NetSuite, and online games.
The easiest way to think of SaaS is like this: it's software, but do you download and install it on your computer, or do you access it using a web browser or mobile app? If the latter, you've likely got a SaaS cloud application on your hands. Note that you don't have control of these applications, short of user-specific application settings. You can't fix bugs in the code or make changes to it. This is the responsibility of the vendor. To some, this lack of control is unacceptable.
If you have an Internet provider, you'll need a desktop or mobile application to access that e-mail, else host it on your own servers. Not only would you have to run an inbound mail server using protocols such as IMAP (or POP for older systems), but you would also need to run an SMTP or outbound mail server. Then you'd have to configure your desktop or mobile e-mail application to connect to those servers, add appropriate levels of security, quota management, etc.
For personal e-mail, people typically select from a variety of free web-based e-mail servers such as Google's Gmail, Yahoo!Mail, or Microsoft's Hotmail, rather than setting up all of the above through their provider. Not only is it "free" (supported through advertising), but users are freed from any additional server maintenance. Another example of SaaS from Google includes their Apps product: office productivity software hosted and run by Google online.
Because these applications run (and store their online), users no longer need to worry about managing, saving, and backing up their files. Of course, now it becomes Google's responsibility to ensure that your data is safe and secure . Other examples of SaaS include Salesforce, IBM's NetSuite, and online games.
The easiest way to think of SaaS is like this: it's software, but do you download and install it on your computer, or do you access it using a web browser or mobile app? If the latter, you've likely got a SaaS cloud application on your hands. Note that you don't have control of these applications, short of user-specific application settings. You can't fix bugs in the code or make changes to it. This is the responsibility of the vendor. To some, this lack of control is unacceptable.
Infrastructure as a Service (IaaS)
On the opposite end of the spectrum, we have "Infrastructure-as-a-Service," or "IaaS," where you outsource the hardware. In such cases, it's not just the computing power that you rent; it also includes power, cooling, and networking. Furthermore, it's more than likely that you'll need storage as well. Generally IaaS is this combination of compute and cloud storage.
When you choose to run your applications at this cloud service level, you're responsible for everything on the stack that is required to operate above it. By this, we mean necessities such as the operating system followed by additional (yet optional services) like database servers, web servers, load-balancing, monitoring, reporting, logging, middleware, etc. Furthermore, you're responsible for all hardware and software upgrades, patches, security fixes, and licensing, any of which can affect your application's software stack in a major way.
When you choose to run your applications at this cloud service level, you're responsible for everything on the stack that is required to operate above it. By this, we mean necessities such as the operating system followed by additional (yet optional services) like database servers, web servers, load-balancing, monitoring, reporting, logging, middleware, etc. Furthermore, you're responsible for all hardware and software upgrades, patches, security fixes, and licensing, any of which can affect your application's software stack in a major way.
Platform as a Service (PaaS)
In the middle, we have "Platform-as-a-Service," or "PaaS." At this service level, the vendor takes care of the underlying infrastructure for you, giving you only a platform with which to (build and) host your application(s). While this service level is the least known or discussed, some feel that this is the most powerful of the three. Gone are the hardware concerns of IaaS, yet with PaaS, you control the application — it's your code — unlike as the SaaS level where you're dependent on the cloud software vendor. The only thing you have to worry about is your application itself.
Systems like Google App Engine, Salesforce's Heroku and force.com, Microsoft Azure, and VMwares Cloud Foundry, all fall under the PaaS umbrella. Not only do these systems provision the hardware for you, but generally, you don't have to worry about those other necessary infrastructure components such as software upgrades, patches, and licensing. Interestingly, what happens when developers use PaaS platforms is that the applications that are created are SaaS applications with.
Users of these apps don't control the code and have just outsourced them to the developer, a PaaS user. You can even generalize this by saying that a PaaS user is a SaaS developer, and to stretch this analogy further, an IaaS user could very well be a PaaS or SaaS developer. Most won't go through the trouble of creating a PaaS platform but will customize this code as part of their SaaS app. And if they reuse their code that interacts with IaaS hardware for other apps, then they've in fact, created a thin (and private) PaaS layer for themselves.
"Cloud computing" is a catch-all term and covers many industries and many different segments. What's more, because it has become a buzzword, many people describe themselves as "cloud computing" no matter how warranted that is.
A public cloud is one in which a service provider serves customers, with functionality like applications, infrastructure, and storage. These services are available to businesses and individuals over the Internet. Public cloud services may be free or offered on a pay-per-usage model; sometimes it’s referred to with the -aaS acronym, meaning “as a Service” as in IaaS (Infrastructure as a Service), PaaS (Platform as a Service) and SaaS (Software as a Service). More on this here: What Cloud Computing Really Is.
This is a scalable service provided by a vendor, designed to be easier to setup and administer with less cost, in addition to reducing waste from lesser used data center resources.
The idea is to eliminate physical location from the data and system access equation. Data from several corporate or individual clients are segmented but do share server space — called, co-location.
The private cloud describes an internal computing model and architecture which provides hosted services similar to those of the public cloud, but reserved for corporate users and those that are approved; essentially, a private cloud is not open to the public and us usually setup behind a firewall. In a sense, this turns the IT department into the service provider or vendor for cloud resources. For those interested in reaping the benefits of virtualized cloud architecture, yet needing more control and security, this is a popular option.
Virtualization and data center automation allows for the scalability, maximizing hardware usage, and flexibility to support internal corporate clients. And, if your organization is so inclined, metering also allows you to charge departments based on their usage.
The decision to pursue cloud computing is one that many organization have or will make as this technology grows and matures. But this decision need not be one fraught with uncertainty. With a little due diligence, and answering a few key questions
Systems like Google App Engine, Salesforce's Heroku and force.com, Microsoft Azure, and VMwares Cloud Foundry, all fall under the PaaS umbrella. Not only do these systems provision the hardware for you, but generally, you don't have to worry about those other necessary infrastructure components such as software upgrades, patches, and licensing. Interestingly, what happens when developers use PaaS platforms is that the applications that are created are SaaS applications with.
Users of these apps don't control the code and have just outsourced them to the developer, a PaaS user. You can even generalize this by saying that a PaaS user is a SaaS developer, and to stretch this analogy further, an IaaS user could very well be a PaaS or SaaS developer. Most won't go through the trouble of creating a PaaS platform but will customize this code as part of their SaaS app. And if they reuse their code that interacts with IaaS hardware for other apps, then they've in fact, created a thin (and private) PaaS layer for themselves.
"Cloud computing" is a catch-all term and covers many industries and many different segments. What's more, because it has become a buzzword, many people describe themselves as "cloud computing" no matter how warranted that is.
Private vs Public Clouds
A public cloud is one in which a service provider serves customers, with functionality like applications, infrastructure, and storage. These services are available to businesses and individuals over the Internet. Public cloud services may be free or offered on a pay-per-usage model; sometimes it’s referred to with the -aaS acronym, meaning “as a Service” as in IaaS (Infrastructure as a Service), PaaS (Platform as a Service) and SaaS (Software as a Service). More on this here: What Cloud Computing Really Is.
This is a scalable service provided by a vendor, designed to be easier to setup and administer with less cost, in addition to reducing waste from lesser used data center resources.
The idea is to eliminate physical location from the data and system access equation. Data from several corporate or individual clients are segmented but do share server space — called, co-location.
The private cloud describes an internal computing model and architecture which provides hosted services similar to those of the public cloud, but reserved for corporate users and those that are approved; essentially, a private cloud is not open to the public and us usually setup behind a firewall. In a sense, this turns the IT department into the service provider or vendor for cloud resources. For those interested in reaping the benefits of virtualized cloud architecture, yet needing more control and security, this is a popular option. Virtualization and data center automation allows for the scalability, maximizing hardware usage, and flexibility to support internal corporate clients. And, if your organization is so inclined, metering also allows you to charge departments based on their usage.
The decision to pursue cloud computing is one that many organization have or will make as this technology grows and matures. But this decision need not be one fraught with uncertainty. With a little due diligence, and answering a few key questions
