Public cloud
  1. Cloud Computing - Introduction
  2. Cloud Deployment Models
  3. Public cloud

 General description

  • Based on a standard cloud computing model
  • Resources are available to the general public
  • Services may be free or offered on a pay-per-usage model
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Public cloud
A public cloud is one based on the standard cloud computing model, in which a service provider makes resources, such as applications and storage, available to the general public over the Internet. Public cloud services might be free or offered on a pay-per-usage model. In general, the infrastructure is owned by a single organization and made available to other organizations.
As discussed in the previous charts, the term public cloud arose to differentiate between the standard model and the private cloud, which is a proprietary network or data center that uses cloud computing technologies, such as virtualization.
Public cloud computing offers easy and inexpensive set-up, a pay-per-usage model, and the scalability needed to meet specific needs.
Public cloud advantages
Many benefits exist using a public cloud architecture.
  • Starting with an easy and inexpensive set-up because hardware, application, and bandwidth costs are covered by the provider. In a highly competitive, global marketplace, businesses with the agility to respond quickest to customers have the advantage, and public cloud services allow them to ramp up and ramp down to meet changing levels of demand in different geographies and markets.
  • An other important advantage is the scalability of the infrastructure in order to meet needs. There is no way for companies to match this level of agility with their internal infrastructure.
  • An other important aspect of public cloud is the readiness of on-demand execution, the fluidity and flexibility of systems delivery. It is really a sense of freedom from the constraints of traditional IT.
  • These public cloud’s advantage include low upfront cost, with practically infinite scalability, and no wasted resources as you usually pay for what you use.
For SMB companies, public cloud services allow them to have applications they normally could not afford because public clouds work well for hosted applications; while private cloud works well for infrastructure, especially when it comes to virtualizing servers and desktops. In addition to that, SMBs turn to managed service providers for help with setting up their private cloud. As generally these companies have limited or no dedicated IT staff and no time or resources to set up the virtualization, automation, storage, and networking technologies to create and support their own a private cloud solution.
Public cloud disadvantages
  • One of the main disadvantage of a public cloud architecture is that it has a significant downside especially in accountability, security, and lock-in and the primary case against enterprise use of public clouds right now is security.
  • Another one is data management. Any enterprise must store and protect critical data and often customer data. They need to ensure their customers that data is readily available when it is needed the most whereas managing the security and integrity of it. Data is frequently driven by government and other compliance mandates. Many public cloud providers exist today and it is difficult to select the right one. It is important to ensure a secure public cloud experience to know who the provider is, their profile, service excellence, and history. Sometimes a service might look compelling and promise substantial savings, but end up costing you more. With public cloud services, you share service responsibility for your business with the cloud provider, so choosing one with integrity, accountability, and strong service-level agreements is critical. Lock-in is referring to vendor lock-in, also known as proprietary lock-in or customer lock-in, which makes a customer dependent on a vendor for products and services, unable to use another vendor without substantial switching costs.
While public cloud services are proving their worth and attracting new converts every day, we will ultimately see the emergence of a hybrid public/private mix that can satisfy any lingering security or regulatory concerns about particular data.