One of the reasons behind some folks pushing for infrastructure as virtual appliances is the on-demand nature of a virtualized environment. When network and application delivery infrastructure hits capacity in terms of throughput - regardless of the layer of the application stack at which it happens - it's frustrating to think you might need to upgrade the hardware rather than just add more compute power via a virtual image.

The truth is that this makes sense. The infrastructure supporting a virtualized environment should be elastic. It should be able to dynamically expand without requiring a new network architecture, a higher performing platform, or new configuration. You should be able to just add more compute resources and walk away.

The good news is that this is possible today. It just requires that you consider carefully your choices in network and application network infrastructure when you build out your virtualized infrastructure.


Last year F5 introduced VIPRION, an elastic, dynamic application networking delivery platform capable of expanding capacity without requiring any changes to the infrastructure.

VIPRION is a chassis-based bladed application delivery controller and its bladed system behaves much in the same way that a virtualized equivalent would behave. Say you start with one blade in the system, and soon after you discover you need more throughput and more processing power. Rather than bring online a new virtual image of such an appliance to increase capacity, you add a blade to the system and voila! VIPRION immediately recognizes the blade and simply adds it to its pools of processing power and capacity. There's no need to reconfigure anything, VIPRION essentially treats each blade like a virtual image and distributes requests and traffic across the network and application delivery capacity available on the blade automatically. Just like a virtual appliance model would, but without concern for the reliability and security of the platform.

Traditional application delivery controllers can also be scaled out horizontally to provide similar functionality and behavior. By deploying additional application delivery controllers in what is often called an active-active model, you can rapidly deploy and synchronize configuration of the master system to add more throughput and capacity. Meshed deployments comprising more than a pair of application delivery controllers can also provide additional network compute resources beyond what is offered by a single system.

The latter option (the traditional scaling model) requires more work to deploy than the former (VIPRION) simply because it requires additional hardware and all the overhead required of such a solution. The elastic option with bladed, chassis-based hardware is really the best option in terms of elasticity and the ability to grow on-demand as your infrastructure needs increase over time.


Often overlooked in the network diagrams detailing virtualized infrastructures is the storage layer. The increase in storage needs in a virtualized environment can be overwhelming, as there is a need to standardize the storage access layer such that virtual images of applications can be deployed in a common, unified way regardless of which server they might need to be executing on at any given time.

This means a shared, unified storage layer on which to store images that are necessarily large. This unified storage layer must also be expandable. As the number of applications and associated images are made available, storage needs increase. What's needed is a system in which additional storage can be added in a non-disruptive manner. If you have to modify the automation and orchestration systems driving your virtualized environment when additional storage is added, you've lost some of the benefits of a virtualized storage infrastructure.

F5's ARX series of storage virtualization provides that layer of unified storage infrastructure. By normalizing the namespaces through which files (images) are accessed, the systems driving a virtualized environment can be assured that images are available via the same access method regardless of where the file or image is physically located. Virtualized storage infrastructure systems are dynamic; additional storage can be added to the infrastructure and "plugged in" to the global namespace to increase the storage available in a non-disruptive manner.

An intelligent virtualized storage infrastructure can further make more efficient the use of the storage available by tiering the storage. Images and files accessed more frequently can be stored on fast, tier one storage so they are loaded and execute more quickly, while less frequently accessed files and images can be moved to less expensive and perhaps less peformant storage systems.


By deploying elastic application delivery network infrastructure instead of virtual appliances you maintain stability, reliability, security, and performance across your virtualized environment. Elastic application delivery network infrastructure is already dynamic, and offers a variety of options for integration into automation and orchestration systems via standards-based control planes, many of which are nearly turn-key solutions.

The reasons why some folks might desire a virtual appliance model for their application delivery network infrastructure are valid. But the reality is that the elasticity and on-demand capacity offered by a virtual appliance is already available in proven, reliable hardware solutions today that do not require sacrificing performance, security, or flexibility.


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