Cloud computing is a new computing paradigm that aims to transform computing into an utility. It is being forecasted that more and more users will rent computing as a service, moving the processing power and storage to centralized infrastructures rather than located in client hardware. This is already enabling startups and other companies to start web services without having to invest upfront in dedicated infrastructure.
However, there is a lot of problems make people flinch to switching to cloud computing, like security, stable of services, etc, while the cloud services providers (Amazon, Rackspace, etc) confirmed the client's data is always safe with their public cloud. The client can trust it but who know what will happen? In April 2011, Amazon has apologized for a fault in its web hosting service EC2, which knocked out many well-known websites. Therefore the wise choice for enterprises is build the hybrid cloud.
There are three types of cloud: public cloud (provided by Amazon, Google, etc), private cloud and hybrid cloud (by combining public and private cloud). Basically, a cloud is composed of three components: IaaS (Infrastructure as a Service), PaaS (Platform as a Service) and SaaS (Software as a Service). In this time, there is a bunch of tools to build a private cloud e.g. Eucalyptus, Appscale, OpenNebula, etc. Most of them are open source and easy to install.
The enterprises want to use their own clouds because of many reason: sensitization data, having full control with services or just because they can be done their job without the power of public cloud. But in many situations the private clouds need some “power” of public cloud, sometime like their private cloud is overloading or out of control, etc. That the good point of hybrid cloud model.
Some clouds provider like Rackspace or Hybrid Cluster provides a complete solution to build the hybrid clouds, but the that service is in beta mode, expensive and in reality the enterprises will rent the server from the provider and deploy their private clouds there, then it is not the real meaning of private cloud.
In this time when people gradually switching to use cloud computing, they can not drop their existing infrastructure, but they can use private and public clouds in parallel. In our research, we propose a solution to build a hybrid cloud with an automatic integrated switch that will enable use the public clouds when the private cloud can not serve.
In experiment, we propose build a private cloud with Ubuntu Enterprise Cloud with the IaaS is Eucalyptus, the PaaS is Appscale and implement a tool in Python that enable switch to use the Amazon EC2 services. All the tools we use in this experiment are open source and free that make easier to approach.
Cloud computing will be popular in next several year, in this time many things are uncertain, we hope our research can contribute a small part in the development of cloud computing.