One of the most important changes in scaling corporate data center has been the evolution of the application delivery controller (ADC). The ADC bridges the network and application environments together. By having the ADC at this strategic control point, organizations are able to scale their data center infrastructure without disrupting the service to the user.
As we move more and applications and infrastructure to the cloud, the ADC will play a similar role in scaling the cloud. As more traffic moves to and from the cloud, the ADC will play an increasingly important role in ensuring that this can happen without degradation of performance. That much is well understood. What’s not well understood is what the form factor of the ADC should be.
Many of the data center appliance vendors have shifted their strategy to build virtual versions. The thought being that if the server and storage infrastructure is virtual, and then so should be all of the appliances that sit around it. This would include ADCs, WAN optimizers, security devices and other functions that surround the server infrastructure.
However, before the industry proclaims, “All hail the virtual appliance”, it’s important to understand there are some limitations to the model of the virtual appliance. With the ADC playing such a key role, it’s critical that cloud providers understand where these limitations are.