While the phrase virtual application delivery controller (vADC) can have a few meanings, it generally refers to
running ADC software in a virtual machine instead of in a hardware-based appliance. While vADCs can add agility and performance to the virtual infrastructure, it isn't right for every environment.
Advantages of using a virtual application delivery controller
One of the potential advantages of a vADC is cost savings, as many vendors claim that vADCs cost roughly 30% less than hardware-based ADCs. Whether or not there is a pricing difference, and how much the savings will be, varies by vendor. As such, the relative cost of a vADC versus an ADC is one of the criteria that IT organizations should use when evaluating vADCs.
Another advantage of a virtual ADC is that it helps to make the IT organization more agile. For example, it is possible to move a vADC between physical servers in roughly the same amount of time that it takes to move a virtual machine (VM). It is also possible to deploy a vADC in less time than it takes to deploy a traditional ADC and in places where it would be difficult to install a traditional ADC—such as in a cloud computing service provider’s data center.
Testing a virtual application controller to for your environment
In most cases, just because an IT organization is considering deploying a virtual ADC does not change the requirements that must be supported. As a result, IT organizations that are evaluating vADCs need to determine if the vADC provides the required ADC functionality as described in the first chapter. IT organizations also need to know what hypervisors the vADC supports.
Perhaps the biggest question that surrounds the use of a virtual application delivery controller is that of performance. There are lots of third-party tests that vendors are using to show whether or not a vADC performs as well as a traditional ADC. The bottom line is that as part of evaluating a vADC, IT organizations need to test the solution in their production environment and measure its performance.
In the final part of this series, read about next-generation application delivery controllers for cloud computing.