Explain with diagram cloud computing stack?
Cloud Computing is a model which enables useful, on-demand network access to shared configurable resources (networks, storage, servers, services, and applications) which can be quickly implemented and released with minimum effort. According to the definition, these are the characteristics every cloud solution should have:
On-demand self-service.
Ability to access the service from standard platforms (desktop, laptop, tablet, mobile, etc.). Resource pooling.
Capability to scale resources in order to cope with demand peaks. Measured billing which is delivered as a service.
This needs to be clearly stated because in the last couple of years as the cloud has continued to explode, many traditional software vendors have tried to sell their solutions as “cloud computing” offerings even though they do not fit the definition. The diagram below shows the widely accepted Cloud Computing stack – it depicts three categories within Cloud – Infrastructure as a Service, Platform as a Service, and Software as a Service.
Cloud Computing Stack
IaaS is the backbone of the cloud. The software and hardware that run the whole show from servers, switches, load balancers, etc. Amazon Web Services is the largest and most well-known in this category (although they do offer the full stack, including PaaS and IaaS).
PaaS is a pack of services and tools made to make coding and deploying applications easy and efficient in the cloud. This is not infrastructure, but rather add-on services that allow you to easier deploy, manage, and scale your infrastructure.
SaaS consists of software applications that are hosted in the cloud and delivered over the Internet to a consumer or enterprise. Microsoft Office 365 is a common example of a SaaS application, although there are countless others.
Infrastructure as a Service (IaaS)
IaaS is an on-demand delivery of Cloud Computing infrastructure (storage, servers, network, etc.). Instead of buying servers, network equipment, space, and software clients buy these resources as a completely outsourced on-demand service.
Here are some main IaaS characteristics:
Resources are delivered as a service Enables dynamic scaling Offers utility pricing model with variable costs Typically includes multiple users on a single piece of hardware.
The largest IaaS providers in the world at the moment are Amazon Web Services, Microsoft Azure, and Rackspace. Here are some situations that are suitable for IaaS:
a company is growing quickly and scaling of resources is too complicated demand is constantly changing – with significant ups and downs in terms of infrastructure demand new businesses without the capital for infrastructure investment
Platform as a Service (PaaS)
PaaS is a platform that enables the creation of different software and applications with ease and without the need to buy the software or infrastructure needed for the job.
Some of the characteristics of PaaS:
Offers services for the development, testing, deployment, hosting, and maintenance of applications in the same environment. Enables UI creation, modification, and deployment with user interface creation tools Multi-user development architecture Offers scalability of used software Subscription and billing tools are also a part of the PaaS PaaS is particularly useful where many developers are working on a project together or where other parties need to interact with the process. It is also commonly used for automated testing and deployment services.
Software as a Service (SaaS)
With SaaS, an application license is provided to customers either as a “pay-as-you-go” model, through a subscription, or as an on-demand service. SaaS is, like other cloud services, quickly growing and soon you’ll be able to find it almost everywhere. For that particular reason, we must know when and where it should be used. Here are the main characteristics of SaaS:
