Platform As a Service (PaaS)

Platform as a service (PaaS) is a category of cloud computing services that provides a computing platform and a solution stack as a service. In this model, the consumer creates an application or service using libraries or/and tools from the provider. The consumer also controls configuration settings and software deployment. The provider provides the servers, networks, storage, and other services that are required to host the customer's application.

Platform Aa a Service offerings facilitate the deployment of services and/or applications without the cost and complexity of managing and buying the underlying software, hardware and provisioning hosting capabilities. All "as-a-service" offerings are characterized as providing low initial cost, self-service, incremental cost as your service usage grows, best practices built-in, resource sharing, management services, automated deployment, lifecycle management, reuse. PaaS provides these capabilities for application and service development.

Figure - Platform As a Service. Source - http://goo.gl/97hmwq

There are various types of PaaS service providers; however, all offer deployment environment and application hosting, along with various integrated services. Services offer varying levels of scalability and maintenance.

PaaS offerings might also include facilities for application development, application design, testing, and deployment as well as services such as web service integration, team collaboration, and marshalling, database integration, scalability, storage, security, persistence, application versioning, application instrumentation, state management, and developer community facilitation.

Besides the service engineering aspects, PaaS offerings cover mechanisms for service management, such as monitoring, discover, workflow management, reservation etc.

Example:

Figure 2 - SaaS, PaaS and IaaS Example. Source - http://goo.gl/FJliOe

Reference: Software company India

Infrastructure As a Service

NIST defines Infrastructure as a service (IaaS) as “The capability provided to the consumer is to provision processing, networks, storage and other fundamental computing resources where the consumer is able to deploy and run arbitrary software, which can include operating systems and applications. The consumer does not control or manage the underlying cloud infrastructure but has control over storage, operating systems and deployed applications; and possibly limited control of selected networking components (e.g., host firewalls).”. The following figure shows the cloud computing layers:

Figure 1 Cloud deployment models

In the most basic cloud-service model, providers of IaaS offer computers – physical or (more often) virtual machines – and other resources. (A hypervisor, such as Xen, OpenStack, Oracle VirtualBox, VMware ESX/ESXi, KVM or Hyper-V runs the virtual machines as guests. Pools of hypervisors within the cloud operational support, system can support large numbers of virtual machines and the ability to scale services down and up according to customers' varying requirements.) IaaS clouds often offer various additional resources such as a virtual-machine disk image library, and file or object storage, firewalls, raw block storage, load balancers, IP addresses, virtual local area networks (VLANs), and software bundles. IaaS cloud providers supply these resources on-demand from their large pools installed in data centers. For wide-area connectivity, customers can use either the carrier clouds (dedicated virtual private networks) or Internet. Lately, this paradigm has been extended towards actuation and sensing resources, with an aim to provide virtual actuators and sensors as a services SAaaS.

To install and deploy their applications, cloud users install operating-system images and their application software on the cloud infrastructure. In this model, the cloud user maintains and patches the operating systems and the application software. Cloud providers typically charge IaaS services on a utility computing basis; cost reflects the amount of resources consumed and allocated. Software company India

Cloud communications and cloud telephony, rather than replacing local computing infrastructure, replace local telecommunications infrastructure with Voice over IP and other off-site Internet services.

Ref : software company in India

Cloud Service Models

The following service models have different strengths and are suitable for different customers and business objectives. In general, interoperability and portability of customer workloads are more achievable in the Infrastructure as a Service (IaaS) service model because the building blocks of this service are relatively well-defined.

A business can now access the entire cloud computing infrastructure it requires as a service for all it uses wherever they are, on whatever device they use. This is called infrastructure as a service (IaaS). User applications remain the same running on more reliable cloud infrastructure; this is when most business will start to use cloud. Apps will be migrated as the existing infrastructure reaches the end of its life. PaaS builds on the power of IaaS as a platform to make it easier to collaborate and develop software. SaaS is explained as a set of fully serviced software running on a fully serviced infrastructure.

There is no longer the need of upfront investments for new business application packages. So cloud can be all the three models with IaaS at the core.

• Cloud Software as a Service (SaaS): The user uses the provider’s applications running on a cloud infrastructure. The applications or software services are accessible from various client devices through a thin client interface such as a Web browser. The consumer does not control or manage the underlying cloud infrastructure including servers, network, storage, operating systems, or individual application capabilities. It might be possible for the user to specify application configuration settings.
• Cloud Platform as a Service (PaaS): This service allows the user to deploy onto the cloud infrastructure applications that the user acquired or created using programming languages and tools supported by the provider. The consumer does not control or manage the underlying cloud infrastructure including servers, network, operating systems, or storage, but has control over the deployed software applications and possibly application hosting environment configurations.
• Cloud Infrastructure as a Service (IaaS): This service enables the user to use processing, networks, storage, and other fundamental computing resources, and to deploy and run other software services or applications, including operating systems and applications. The consumer does not control or manage the underlying cloud infrastructure but has control over operating systems, deployed applications, storage, and possibly limited control of select networking components such as host firewalls.

 Reference: custom software development company India

Virtualization

Virtualization is base technology of cloud computing. Following video explains what is virtualization, types, its objective and various approaches.

Resources:
1. Virtualization - a base technology of cloud computing - Presentation
2. Virtualizatoin - a base technology of cloud computing - Video
3. Custom software development company India

What is Cloud?

Cloud is viewed as future technology. Following video explains what is Cloud technology, its importance and service models.

One can also download this presentation at 

Cloud technology presentation

Cloud Technology Video

Custom software development company India

What is  Cloud?

As defined by the National Institute of Standards and Technology (NIST), “cloud is a model for enabling convenient, on-demand network access to a shared pool of configurable computing resources that can be rapidly provisioned and released with minimal management effort or service provider interaction.” (Microsoft, 2014)

Cloud computing is a pay-per-usage model. Cloud overcomes the traditional IT bottlenecks like the rooms full of data storage, firewalls and routers along with the teams to support it, when there were needs to invest in upgrades and rebills.

Figure 1 - Cloud computing (computing, 2014)

Deployment Models

History reveals a similar shift happened at the way business used power at the turn of the century. Business no longer has to build, buy or manage costly computing facility on site. Just as business learnt that power provided by a specialized power company improved reliable quality, cloud computing has proven to be more reliable, more secure, more scalable and ultimately more affordable than traditional onsite IT. This is why most new business apps and softwares are now deployed on cloud. Custom software companies in India has also started recommending cloud.

The following deployment models present a number of trade-offs in how customers can control their resources, and the scale, cost, and availability of resources.

1.      Private cloud: The cloud infrastructure is operated solely for an organization. It may be managed by the organization or a third party and may exist on premise or off premise.

2.      Community cloud: The cloud infrastructure is shared by several organizations and supports a specific community that has shared concerns (e.g., mission, security requirements, policy, and compliance considerations). It may be managed by the organizations or a third party and may exist on premise or off premise.

3.      Public cloud: The cloud infrastructure is made available to the general public or a large industry group and is owned by an organization selling cloud services.

4.      Hybrid cloud: The cloud infrastructure is a composition of two or more clouds (private, community, or public) that remain unique entities but that are bound together by standardized or proprietary technology enabling data and application portability.

5.      On-site private cloud: The security perimeter for this deployment model extends around both the subscriber's on-site resources and the private cloud's resources. The private cloud may be centralized at a single subscriber site or may be distributed over several subscriber sites. The subscriber implements the security perimeter, which will not guarantee control over the private cloud's resources, but will enable the subscriber to exercise control over resources entrusted to the on-site private cloud.

Cloud computing challenges

One can easily understand from previous discussion that it’s very beneficial for a company to adopt any of the ACT as per requirement. However it has been witnessed that majority of software companies in India have developed some kind of resistance in adopting the same in their work environment. This is more prevalent in small scaled industries. The resistance is because of following challenges/issues levied by ACT.

Challenges faced by ACT:

1.      Security Issues:
By any chance if intruder get access of cloud’s server or find vulnerability of cluster and start attacking them, it’s very difficult for small scaled organizations to take real-time steps against those attacks due to lack of sufficient funds, unavailability of trained human resources or Information security experts to fight against those.

2.      Data theft or misuse of data:
Data and information is the most important asset for all kind of industries. In spite of existence of strict policies and frameworks, companies find it very difficult to put confidential data in the hands of others. There are possibilities of data being misused by the hosting or cloud companies.

3.      Availability:
Cloud requires the availability of internet connectivity for the services to work. Good and reliable internet connectivity is not available in majority of countries. This puts restriction on various companies to use cloud for their daily operations and activities.

4.      Reliability

Reliability of cloud services heavily depends on good and reliable internet connectivity.

Security, downtime, poor network or connectivity etc. are very common issues facing by internet connectivity esp. in developing countries. So, it’s very hard for any company to just rely on cloud services

On top of above challenges, following are few other reasons that is hindering the acceptance of cloud and ACT.

1.    Lack of information – many companies does not have information or knowledge about what and how cloud computing or ACT can help them to perform better. This is more prevalent in small scaled industries due to lack of skilled manpower and information sources.

2.      Myths – companies have developed certain myths and wrong assumptions about this technology. Few of them are real challenges however many are just myths developed due to low quality information.