Cloud services, what are they? We immediately give a definition of Cloud Architecture. Cloud Computing is an architecture model characterized by the attribution of dynamic resources. The Cloud Computing infrastructures are large data centres that allow the user to have the resources they need (storage, applications, programs, services) according to need. In this way, the company can considerably reduce the investment in internal infrastructure to acquire it, externally, based on the needs of the moment.

The resources are not fully configured and implemented by the supplier specifically for the user, but they are assigned starting from a set of resources shared with other users, leaving the user to part of the burden of configuration. When the user releases the resource, it is reconfigured in the initial state and made available again in the shared pool of resources.

The Cloud Computing makes available to the user resources as if they were implemented by systems (servers or personal devices) “standard.” The actual implementation of the resources is not defined in detail. Indeed, the idea is that the implementation is a heterogeneous and distributed whole – the cloud, in English cloud – of resources whose characteristics are not known to the user.

Cloud services, here are the main actors and 3 types of services offered

In this definition we can recognize three different actors that interact in the process:

• The service provider (cloud provider) that offers services (virtual servers, storage, complete applications) generally according to a “pay-per-use ” model;
• The administrator client who chooses and configures the services offered by the supplier, generally offering added value such as software applications, advanced configurations and customizations;
• The end customer who uses the services properly configured by the administrator client.

In some situations, the managing client and the end customer may coincide.

Within the definition of Cloud architecture we can distinguish three basic types of services for Cloud Computing:

• Infrastructure as a service (IaaS)
• Platform as a service (PaaS)
• Software as a service (SaaS)
• Service 1: Software as a Service (IaaS)

In this type of service, customers do not pay for the possession of the software but for the use of the same. Access to the software is possible via API or often via Web service or REST. SaaS is a set of means, services and skills that allows companies to completely outsource certain aspects of their information system (messaging, security and more) and replace it with an operating cost rather than a real investment.

Service 2: Platform as a service (PaaS)

For Platform as a Service (PaaS) refers to the delivery to the customer of an entire Cloud Platform, to which the user has access via a particular framework distributed.

It can be used to write applications to be distributed through a managed system thanks to which the platform is able to increase resources or reduce them based on requests. The PaaS elements allow to develop, test, implement and manage company business applications without the costs and complexities associated with the purchase, configuration, optimization and management of hardware and software Basic. The PaaS elements can be used for the design, application development and application services such as team collaboration, Web integration, database integration, security and state management. These services can be used as an integrated solution on the Web.

Service 3: Infrastructure as a service (IaaS)

Infrastructure as a service (IaaS) is a supply model in which an organization takes outside the equipment used for various operations, including storage, hardware, servers and network components. The provider provides the resources and is responsible for the safekeeping, execution and maintenance.

Cloud services, how to plan migration: 2 approach strategies and benefits of the use

The approach to the Cloud depends on many variables, such as the type of provider to contact (public or private cloud) and the type of service. Finally, it also depends on how to integrate the internal infrastructure and data management with security and privacy. Despite these variables, two approaches can be identified:

• An internal path, which starts from the creation of Cloud infrastructure and the transfer of existing applications, to then choose which services to continue to supply internally and for which the Public SaaS model is appropriate
• An external path, which immediately provides for the testing of Public SaaS services and then subsequently the adoption of PaaS services.

In general, the structural approach is the one undertaken by larger companies, as they have the skills to control resources, more restrictive constraints with regards to security and privacy management policies, the financial resources necessary for initial investments, more processes rigid, greater architectural complexity and a demand for IT services that requires the exploitation of economies of scale enabled by the Cloud.

For small companies or in the case of start-ups, the infrastructure path will be more difficult to implement due to the high initial costs and the lack of adequate architectural skills. These companies will probably be attracted by Public Cloud- type services, through which they can access, in a pay-per-use manner, solutions that previously were not economically and/or technically accessible. This does not necessarily mean that in the long run, the company will have savings, but at least in the short term, it will have access to solutions that in the traditional IT model would have been precluded by very high initial investments and the lack of adequate skills.

What are the advantages that companies expect:

• Reduction of service activation times
• Reduction of internal management costs
• Lower initial investments
• Scalability and flexibility

The Cloud has a potential that is fully realized only when companies develop a clear vision of the Cloud, both from a technological and business point of view. The key word is transformation: the Cloud architecture facilitates the company to keep pace with technological progress and to evolve.

Cloud services, critical aspects and difficulties. But often they are not chosen because they do not know each other

The critical aspects essentially concern security and privacy:

• Where is the data physically stored?
• Who can access them?
• With what rules and safeguards?

Although in reality the problems highlighted by IT managers mainly to the difficulty in defining and maintaining SLAs

At the business level, the greatest difficulty is linked to cost forecasting, in particular for small businesses with linear growth.

• Both for performance and reliability of the network and ICT providers, as most of them as Service solutions require the availability of broadband internet connection technologies, which guarantee a high level of service
• Both for the scarce knowledge of the solutions by the user companies: in over half of the cases of companies that do not use Cloud solutions, failure to adopt is linked to the lack of knowledge of the model and the opportunities it offers.