If you need special software, it isn’t cloud computing. If you need hardware, apart from your trusty laptop, it isn’t either. All you should need to do whatever you want is an internet connection.
This idea is alluring and the key concept behind cloud computing.
However, the term appears to cover just about anything on the internet. Vendors are all clamouring to claim their products are in the cloud. All, rather confusing.
To understand the cloud computing market I found the NIST Definition of Cloud Computing (v15) invaluable.
Essential characteristics
There are five key properties:
- On-demand self-service – consumers can increase or decrease use at will. Provider not needed to help.
- Broad network access – users can access it via the network using standard methods.
- Resource pooling – the computing resources are shared and can be housed anywhere.
- Rapid elasticity – consumers can request seemingly unlimited resources at will. No size or time limits.
- Measured service – the system automatically monitors and optimises usage. These measurements provide transparency for both the consumer and provider.
Service models
There are three service models for providing cloud computing:
- Software as a Service (SaaS) – The consumer runs the provider’s applications. The consumer does not control any part of the systems. They can make application configuration changes.
- Platform as a Service (PaaS) – The consumer deploys and runs applications; either bought, or created using the provider’s programming languages or tools. The consumer does not control any part of the systems. They can control deployed applications, and possibly the application-hosting environment.
- Infrastructure as a Service (IaaS) – The consumer uses the provider’s systems such as: processing power, memory, storage, and networks. The consumer can run arbitrary applications. These applications include operating systems. Consumers may have limited access to the networking systems.
Deployment models
There are four deployment models for cloud computing:
- Private cloud – the systems exists for the sole use of a specific customer.
- Community cloud – several consumers, with a shared interest, share the systems.
- Public cloud – the systems are open to the public.
- Hybrid cloud – the system is a combination of two or more different deployment models.
Benefits
Some benefits include:
- Reduced costs – you only pay for what you use.
- Scalability – you can increase or decrease your use as you wish.
- Better mobility – you can access the services from anywhere.
Drawbacks
There are some risks to think about before jumping in.
- Security – you no longer control all access to services.
- Quality of Service (QoS) – other users may affect your service levels.
- Service lock-in – at present there are no commonly agreed Application Programming Interfaces (APIs). This may lock you into specific providers.
As a concept cloud computing is simple. However, as always, the devil is in the details.
Cloud computing offers much, but don’t overlook the risks
