As SAP has positioned itself as one of the leading cloud service provider, cloud computing is getting a lot of attention from CIOs and line of business (LOB) leaders who are already showing a great amount of interest in this topic. CIOs and LOB leaders are now interested to find out how they can take advantage of the cloud computing and extend their business to the cloud, make their business more agile and reduce time and cost for deploying new applications. Being a beginner in the cloud computing area, I started reading tons of blogs available on this topic on the web and in SAP community network and learned a great deal about what SAP stands and what it has to offer in terms of cloud computing. But, then I realized that I need to take a step back and first understand the basic definitions and fundamentals about cloud computing and move on from there. If you are like me, a beginner in the cloud computing, then please join me as we start this journey...
As per National Institute of Standards and Technology, the cloud computing is defined as : "Cloud computing is a model for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services) that
can be rapidly provisioned and released with minimal management effort or service provider interaction. This cloud model is composed of five essential characteristics, three service models, and four deployment models"
Now that we know the technical definition of cloud computing, let us try to understand some of its key characteristics that makes it so popular.
On-demand self-service: customer (subscribers) can use web based portal to request cloud resources (server time and network storage) as needed without any human interaction.
Broad network access: cloud computing resources are available over the network and can be accessed using all kinds client platforms e.g. mobile and desktops.
Resource pooling: Computing resources (e.g. storage, processing, memory, and network bandwidth) are pooled to serve multiple consumers using a multi-tenant model. Multi-tenancy can be economical for customers and at the same time if offers flexibility whereas new resources can be assigned or reassigned based on customer demand.
Elasticity: Resources are provisioned and released on-demand and/or automatically based on certain parameters.
Measured service: Resource usage can be monitored, controlled, and reported, providing transparency for both the provider and
consumer of the utilized service (1).
Cloud computing is available mainly in three service models:
Infrastructure as a Service (IaaS): Cloud service provider provides its customer servers, network, storage and other computing resources aka infrastructure which is managed solely by the cloud service provider. The service provider owns the equipment and is responsible for housing, running and maintaining it. The client typically pays on a per-use basis. Customer can run operating systems and application of their choice and have control over it.
Software as a Service (SaaS): the customer can use the provider’s applications running on a cloud infrastructure. The applications are accessible from various client devices through either a thin client interface, such as a web browser or a program interface. The customer does not manage or control the underlying cloud infrastructure or even individual application capabilities, with the possible exception of limited user specific application configuration settings.
Platform as a Service (PaaS): Platform as a Service (PaaS) is a way to rent hardware, operating systems, storage and network capacity over the Internet. The service delivery model allows the customer to rent virtualized servers and associated services for running existing applications or developing and testing new ones. Geographically distributed development teams can work together on software development projects. Services can be obtained from diverse sources that cross international boundaries. Initial and ongoing costs can be reduced by the use of infrastructure services from a single vendor rather than maintaining multiple hardware facilities that often perform duplicate functions or suffer from incompatibility problems. Overall expenses can also be minimized by unification of programming development efforts (4).
Private cloud. The cloud infrastructure is created for and to be consumed by single organization.
It may be owned, managed, and operated by the organization, a service provider, or some combination of them, and it may exist
on or off premises.
Community cloud. The cloud infrastructure is created for and to be consumed by a community of organizations who share common mission and objectives.
It may be owned, managed, and operated by one or more of the organizations in the community, a service provider, or some combination of them, and it may exist on or off premises.
Public cloud. The cloud infrastructure is created for and is available for consumption by public. It exists on the premises of and is managed by the cloud service provider.
Hybrid cloud. The cloud infrastructure is a composition of two or more distinct cloud infrastructures (private, community, or public).
I hope now you have good understanding of the fundamentals of cloud computing and the choices it offers. In the next part of this series, I will try to explore the cloud offerings from SAP and how they fit in with different cloud service and deployment models.
- 1. http://thoughtsoncloud.com/2014/01/cloud-computing-defined-characteristics-service-levels/
- 2. http://csrc.nist.gov/publications/nistpubs/800-145/SP800-145.pdf
- 3. http://searchcloudcomputing.techtarget.com/definition/Infrastructure-as-a-Service-IaaS
- 4. What is Platform as a Service (PaaS)? - Definition from WhatIs.com