Virtualise the application delivery controller

Look beyond server virtualisation when aiming for datacentre savings, says Amir Peles

CIOs and IT managers in my view are in a constant struggle to balance the need to expand the IT infrastructure to support a growing business with a lack of datacentre floor space and the need to cut operational costs, such as electricity and cooling.

Virtualising server hardware means IT staff can consolidate 10, 15 or even 20 physical servers into one server running multiple virtual server instances or virtual machines. Of course, this may also make their organisation much greener.

Server virtualisation is the first thing which comes to mind when discussing virtualisation within the datacentre. Application delivery controller (ADC) virtualisation means organisations will need less ADC hardware – also reducing the costs of property, power, cooling and spare parts.

Consolidating six traditional ADC devices into one virtualised ADC device running six virtual ADC instances (vADCs) means that IT organisations can save up to 4200kWh of their power consumption requirements on a multi-year project.

But I believe you need to ensure the ADC vendor offers multiple virtualisation options. ADC may be provided as a virtual appliance (software-based ADC) that can run on the existing server virtualisation infrastructure, or as an ADC device that allows for the consolidation of multiple ADCs through virtualisation.

I believe the ADC offering should support server offloading capabilities such as SSL encryption and decryption, which when offloaded to the ADC saves a lot of server CPU and power consumption.

I also believe you should ensure the ADC virtualisation offering will not compromise the resilience or performance predictability of the ADC services. This is a risk in the consolidation of ADC hardware.

This can be achieved by ensuring complete fault, network and management isolation between the different virtual ADC instances.

Verify that a resource guarantee mechanism exists that will ensure each virtual ADC instance is allocated within a dedicated resource for its operation. This way, every virtual instance can use only those resources for which it was specifically allocated, helping along the performance.

Ensure that integration with the virtual datacentre management system is supported, as well as correct traffic redirection whenever virtual machines are moved either within the datacentre or to another datacentre.

This will help make further savings by moving application workloads to a minimal set of servers or a cheaper location.

IT providers should ensure that through the consolidation of customer hardware ADCS, the customer does get those savings.

ADC virtualisation can achieve the same IT benefits as server virtualisation within the application delivery layer.

Amir Peles is chief technical officer at Radware