As mentioned in my post titled, Virtualization and Green Computing, green computing the industry catch phrase for finding ways to make the most efficient use of computing resources. In this post, I'd like to look at access virtualization and the role it plays in green computing. Access virtualization, by the way, is using hardware and software to allow individuals to access applications from just about any device over just about any network withing requiring the application or the user access device to know too much about one another. Although there are a number of different hardware configurations typically deployed to support access virtualization, in all cases individuals' access device always runs either a small software agent or a plugin for a Web Browser. The application is actually running somewhere else in the network either on a blade computer or a general purpose server. Virtual access software runs on either the blade or the general purpose server and "hijacks" the user interface. The user interface logic is transformed into a neutral form and then sent out on the network. Any device supporting the agent or Web Browser plugin can access the application being virtualized by the access virtualization software. This approach provides quite a number of benefits including the following:
- Freedom to select the most appropriate access device — applications may be accessed by just about any type of device ranging from a handheld smartphone to a deskside computer. Some sophisticated versions of access virtualization software can save the state of the application allowing individuals to start an application on a deskside or laptop computer and pick it up on a smartphone.
- Freedom to access just about any time of application — a Windows application could be accessed by an individual using a thin client or even a Linux-based desktop system. A mainframe application that expects to communicate with a 3270 class device might actually be communicating with a Smartphone, such as a Treo or a Blackberry.
- Freedom to select the most appropriate networking technology — individuals can acess virtualized applications over just about any type of network including WiFi, LAN, mobile telephone network or if the appropriate interface can be found, lime jello (alright, I'm kidding about Jello communications).
- Application processing can be centralized — Applications are actually running on blade computers or general purpose computers that are housed in a safe, managed place. This approach makes it much easier to prevent mischief. It also means that installing and updating software no longer has to become a road trip for some hapless systems person.
- Client hardware costs can be reduced — individuals can access applications from thin client devices that consume less power, are smaller and are less costly that some personal comptuers. It is not necessary to update these devices when new generations of operating systems or applications are installed.
- Application servers can be shared — depending upon the access virtualization software selected, a server might be able to support 20, 30, 40 or 50 client sessions reducing the number of physical systems that must be managed and maintained. Obtaining this benefit usually requires the use of application virtualization and/or processing virtualization software.
As with other forms of virtualization, this is not new. It clearly is an outgrowth of IBM's terminal cluster controllers from the late 1960s and DEC's terminal servers from the early 1980s. Some suppliers, such as Citrix, Microsoft and the open source Linux Terminal Server Project are proponents of a software-based approach. Other suppliers, such as ClearCube, HP and NeoWare are proponents of a more hardware focused approach. Where's the tie-in to green computing? Organizations reduce costs of administration, operations and costs due to software maintenance. Since fewer computers needed the endangered kilowatt is preserved and far fewer BTUs, Calories or Joules are released into the wild. Is your organization using access virtualization? Have you actually saved money? Have you actually improved levels of security? Do you have any wonderful stories about accessing complex applications from a smartphone?