Cloud computing is a technology where applications are deployed on immutable servers which increases performance and reduces time spent with long difference. Cloud computing itself referring to a related term ‘public cloud’ is delivering the computing as service rather than as a product. It enhances the manageability and requires less maintenance by adjusting resources which meets varying industry demands. This service hides many of the complexities of running background task like Amazon web service Lambda. The market share of cloud computing is expected to exceed $59 billion in 2015.

The classification of Cloud Computing services can be done in three parts:-

• Software as a service (SAAS) : SaaS web delivery model eliminates the need of installing and running an application on individual server. With SaaS model maintenance and support can be streamlined because Application, Data, Storge, Middleware, virtualization everything is managed by vendors.e.g.Microsoft365 and GoogleDocs.
• Platform as a service (Paas) : These services are used to access from web browser. PaaS provider host hardware and software infrastructure and business rely over them for key services.Salesforce.com is common PaaS provider which provides Customer Enterprise relationship management. IT teams do not need to purchase and set up server from scratch rather data can be accessed from provider’s server. This can raise the security and data leak threats but these risks can be mitigated by choosing a host with security accreditation and properly applying data encryption techniques. PaaS providers offer Managed Linux and Windows OS which allows more resources for development and fewer to maintaining or configuring the operating system.
• Infrastructure as a service : In this service virtualized resources are provided over the internet.IaaS provider host hardware, software, servers, user’s application and handle task of resilience planning .It automates the administrative task and policy based services. Although IaaS is similar to PaaS, the difference is that here more control is provided over operating system.

As with growing industry demand ,Many stalwarts of hosting industry have started providing Cloud hosting service some top cloud hosting providers are :-

Lock-in: A biggest Concern:-

Cloud service enable to build large infrastructure form micro-services without worrying about underlying communication and infrastructure between them. The core concern while adopting these services is lock-in to a specific provider.

• Even if we build infrastructure over standard framework and tools we have to go through process of transferring data, DNS changing.
• Some services bound their customer to code level lock-in which requires to build application in specific way tightly integrated to their infrastructure and tailored to their system.E.g Google App Engine
• Some services like Amazon web service Lambda provides architectural lock-in but less code lock-in. In first iteration of Lambda we have to write node.js function and these functions are invoked either by and API or specific events. This can lead to hundreds of small function. Here the hurdle is that we can’t take those functions and run them on other provider system. To make them run it is required build our own system around them which generates highly architectural lock-in.

An architecture oriented on micro-services which is built on technology that can be used on variety of provider can offset many of trade-offs. Building on top the service initially and moving parts of service to somewhere else for better control may be the approach but it require a different approach.

How your business is really getting impacted:-

• One of the biggest advantages of cloud is that it is off-site and remote hosting which is preferably used in Content distribution network (CDN).These CDN can improve user experience for mobile and web applications and content.
• On cloud hosting user is supposed to use dynamically allocated resources. A dedicated resource can be provided on demand of the customer. Consequently hosting provider are able to render various hosting package which satisfies varying industry needs and user ends up with paying only for resources which he has used.
• It increases resiliency and enables offsite backup at distributed data centers at different locations establishing DRBC (Disaster recovery and business continuing) platform.
• No cloud provider is same. Each one offers different sort of packages. To find out which fits the best, you must analyze use cases. Choose the hosting provider which best fits your IT needs.

As cloud dominantly adopting the market, also unraveling some critical technical challenges for industry:-

• Different platform of cloud cannot be compared relatively due to the lack of common methodology to measure capability.
• Performance cannot be assessed throughout the life cycle of infrastructure.
• SLA’s (Service Level Agreements) are based on availability instead of capabilities of service provided.

CLoudQos is first solution which is addressing the requirement of entire cloud system by providing enterprises, hosting provider and cloud service providers the data ensuring if they are selecting best cloud service.

There could also be some criteria for selecting cloud provider:-

Geographical aspect : While purchasing cloud you should ensure where physical data center is located. Data center located at another country or region may fall and abide under the jurisdiction of that area.

Storage : Storage technology is also a big concern while opting for cloud. You must ask your provider for storage technology they are using .Is it redundant? If it is then how are they going to encounter disk failures? Moreover check for SSDs (Solid state drive) if they are available or not?

Issue with Hypervisor : You should enquire about the hypervisor being used. Many applications are supported for only compatible hypervisor. Some hypervisor also provides features that can protect server even at the event on which host is running gets failed. If you are moving you hosting to another provider then it should be checked if existing service is available?

Network Connectivity : Network Connectivity may also be the crucial topic to check on. If provider has more than one uplink to provide the connectivity then it will be helpful at the time of outage. Along with network uptime it is also worth to consider the bandwidth charges which is often hidden in hosting price.

Support : While taking hosting it is need to get acquainted of the support being provided if it is email or a phone help line. If your service is running 24/7 then make it sure if provider is giving 24/7 support. You may also check if provider is member of bodies or code of practices. E.g. SSA certification body.

Whether it is impossible to conduct a questionnaire but it is recommended to ask for essential things before taking service on lease which can ensure you from falling into bigger loss.