Cloud Service Models

what are cloud service models, what are different types of cloud service models, IaaS, SaaS, PaaS, comparison of IaaS, PaaS and SaaS

CLOUD SERVICE MODELS

What are service models exactly? Service models are the way by which the cloud is offering its services to the end-users. Before the cloud, there are on-premise environments in which the entire infrastructure from the networking to the applications. It is getting deployed and handled by the organizations themselves. But with the coming up of the cloud, there is infrastructure as a service, platform as a service, and software as a service. These are the three service models by which the infrastructure or the platform or the software or the cloud provides the users with the service.

Infrastructure as a Service (IaaS)

Infrastructure as a service gives you a server in the cloud (virtual machine) that has complete control over it.

Here if you see the networking, the physical network, the servers, the physical storage on the physical servers, and the virtualization of the servers. It is managed by the cloud vendor. So you or your organization is going to choose what OS needs to deploy and from the operating system. You will have full control to decide what middleware, runtime, what kind of database or data structure and what kind of applications to deploy.

E.g. Amazon Web Service, Microsoft Azure, Google Compute Engine, Digital Ocean, Rackspace, etc.  

When you have infrastructure as a service given to you by the cloud that taking care of a virtual machine or a cloud server or environment. In the cloud environment, you have full control, you can deploy whatever applications or install many applications. But the only thing is you need to be in charge of the server. So these are your virtual machines on Infrastructure provided to you as a service. IaaS is preferable when you want to extend your physical data center into the cloud.

Infrastructure as a service gave us a trade-off between control and responsibility. Keeping in mind that part of the value proposition was to reduce the amount of responsibility required for us to maintain the right amounts of control over our infrastructure. Somewhere between is a magical opportunity to save money, improve efficiency, and reduce the amount of work that we have to do to deliver.

Platform as a Service (PaaS)

In PaaS, for example, we are hosting a website and do need a virtual machine and don't want to manage a virtual machine. We need only a hosting space like GoDaddy to register for a domain. It is addressed as your domain gives a URL whatever you choose. It also gives some space like 50 GB 50 MB whatever to host files. So a similar kind of thing is also possible in Azure.

E.g. AWS Elastic Beanstalk, Apache Stratos, Google App Engine, Windows Azure, etc.

So here it will give you space, a path in which you can upload your code, upload your files. It will give the link or the URL to the website the code will be running in the background. In the background, a virtual machine and a web server are running but Azure manages and maintains that server. So you don't have to own the server or worry about upgrading, patching, server going down any issues of the server.

There are two components: application files which will be deployed to the cloud, source code, DLLs, and a configuration file in which you will be having a configuration for your application. These two combinations are for your web roles and worker roles.

Web Role

Web role is nothing but a web server or as your virtual machine that is pre-configured as a web server may be running IIS. It will automatically have your application loaded on it. By the time the server spins up the server. One thing you need to start your web application and a little spin of the server. So this will create a public endpoint, a URL for your application and it could also be an API. With the cloud services as your handles all the operating system details, upgrading, batching, and everything.

Worker Role

The worker roles are some services that run alongside your web browser. These are responsible for performing the computing functions to support your application. By getting your telemetry data you are not requesting the user and giving it to the server. Whatever things happen in the background is done by the worker. So this is the structure of the platform as a service.

Software as a Service (SaaS)

Many of the applications such as Google or Facebook. Everything is a software service you are using the software as a service. Installing the client on your mobile devices. When you upload a file into Instagram or you upload a file into Facebook it doesn't stay on your device. It gets uploaded to the cloud and it is available in the cloud. So you are provided software as a service.

For example, Facebook we are responsible for managing. And not worry about what was machine is it running is a Linux machine or a Windows machine. What kind of services they are hosted if servers are running in which database. We need only what software to use. Another one is Webmail anytime you are using a web browser to interact with an application. Software as a service example mobile applications that you might find in the Google Play Store or the Apple Store. These are also great examples of software as a service.

E.g. Google Apps, Salesforce, ZenDesk, Slack, BigCommerce, Hubspot, Google G Suite, etc.

The vendor manages the entire structure here from networking to the application and needs to worry about my application. Let it be Office 65 or Salesforce or websites and these are a software as a service.

Apart from these three major service models. There is Database as a service, Chatbot as a service, cognitive services, search services and a lot of other services are there. But these are the three fundamental and major service models in the cloud which provide the services of the cloud.

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