6. Replicating Virtualized Database Servers

In general, virtualization technology is increasingly being used to improve the manageability of software systems and lower their total cost of ownership. Resource virtualization technologies add a flexible and programmable layer of software between applications and the resources used by these applications. One among several approaches for deploying data-intensive applications in cloud platforms, called the virtualized database servers approach, takes advantage of virtualization technologies by taking an existing application designed for a conventional data center, and then porting it to run on virtual machines in the public cloud. Such migration process usually requires minimal changes in the architecture or the code of the deployed application. In this approach, database servers, like any other software components, are migrated to run in virtual machines. One of the main advantages of this approach is that the application can have full control in dynamically allocating and configuring the physical resources of the database tier as needed. Hence, software applications can fully utilize the elasticity feature of the cloud environment to achieve their defined and customized scalability or cost reduction goals. In addition, this approach enables the software applications to build their geographically distributed database clusters. Without the cloud, building such in-house cluster would require self-owned infrastructure which represent an option that can be only afforded by big enterprises.