The Growing Trend in vADC Density

Over the past 2 years, Radware has offered virtualized ADC appliances with virtual ADC instances that can be used on hardware appliances or on general-purpose servers. During this time, we’ve noticed two schools of thought emerging on the all-important question of vADC density. The first, argues that vADC density is one of the key criteria to consider when evaluating a virtualized appliance. The second, however, claims that organizations will typically avoid utilizing density higher than 10-16 vADC on a single piece of hardware. In search of greater clarity, we went back after implementing hundreds of ADC consolidation and virtualization projects with thousands of vADCs to check and see if there were any identifiable trends in vADC density deployment.

The graph below shows what we found:

What the chart makes clear is that the deployment of vADCs per Gbps is consistently growing. As customers become more familiar and confident with ADC virtualization, they increase the number of vADCs deployed on their appliances. In fact, many customers who started with ADC consolidation eventually deployed a greater number of vADCs than they originally had as ADC appliances.

This can be attributed to the following:

1. Organizations have become more familiar with the technology.
2. The cost per vADC is significantly lower than the cost per ADC device. As a result, organizations can afford to use the ADC service in front of more applications.
3. Customers recognize the value of ADC virtualization such as ease of operation, faster application roll out and application SLA.

In addition, we’ve observed customers using high vADC density in a number of ways:

1. vADC per consolidated device – Typically this is the initial way vADCs are deployed.
2. vADC per application – Since it is now affordable to allocate a separate vADC for each application.
3. vADC per application development stage – Since Radware vADCs all have the same feature set, many organizations use a vADC for each stage in the development cycle, easily moving the application and its resources between stages.

Overall, it looks like the market’s adoption of ADC virtualization is very similar to the ways in which server virtualization evolved. While the initial driver is the cost savings benefit offered by consolidation and the move to a virtualized infrastructure, shortly after deploying this technology, organizations can see increasing gains in both business agility and operational simplicity.