Data Center

What is Application Virtualization?

Just like Desktop Virtualization, where individual desktop sessions (OS & Applications) are virtualized and run from a centralized server, Application Virtualization virtualizes the Applications so that, i. It can either be run from a centralized server (or) ii. It can be streamed from a central server and run in an isolated environment in the desktop itself. Let us find out more about Application Virtualization, in this article.

As mentioned above, there are two types of Application Virtualization:

i. In the first type of application virtualization, application image is loaded on to a central Server and when a user requests the application from his computer, it is streamed to an isolated environment on the user’s computer (or similar devices) for execution. The application starts running shortly after it gets sufficient data to start running, and since the application is isolated from other applications, there may not be any conflicts.

The applications that can be downloaded can be restricted based on the User ID which is established by logging in to corporate directories like AD/ LDAP. This also provides for centralized single image deployment and management. More over, with most of the AV (Application Virtualization) vendors, administrative privileges are not required to run new apps on the local PC ensuring that the users do not meddle with other settings.

Once the applications have been downloaded, used and closed, the applications, settings and profiles are still saved in the user cache to enable subsequent / off-line access to those applications. The updates / patches are applied to the server image and when the users request the application after updation, they receive the newer version. If users are not sure about the application compatibility to OS after updating, they could revert back to the older version – if it is retained on the server.

Another advantage is the ability to run in-compatible versions of applications on the same computer (Office 95/97 and Office 2007, for example). Similarly, if certain applications might require different versions of Java (for example), these applications cannot run on the same computer – but application virtualization makes it possible.

The list of applications available to the user is maintained in a GUI based window on the computer connected to the network, and the users can stream and run any application from that list, when ever they want.

ii. In the second type of application virtualization, the applications are loaded as an image in remote servers and they are run (executed) in the servers itself, and only the on-screen information that is required to be seen on the computer is sent over the LAN. This is closer to desktop virtualization, but here only the application is virtualized instead of both application and operating system.

The biggest advantage of this type of application virtualization is – the underlying Operating System in the user’s computer doesn’t matter for executing any application as the applications are processed in the server. Another advantage is the effectiveness of mobile devices (mobile phones, tablet computers) etc that have lesser processing power while running processor hungry applications, as these are processed in the powerful processors of the servers.

If Server Virtualization is combined with this type of Application Virtualization, there is an added benefit of consolidation of the total number of servers required to run all the enterprise applications (vs individual servers for individual applications) and High Availability of applications, as they can be migrated to other servers in case of hardware failures in the Server. But Server Virtualization has its own overheads and hence there might be a small decrease in the performance levels, depending upon the AV vendor.

Also, as the application resides and executes in the Servers in the Data Centers, firewall policies and centralized security policies can be applied to them. Besides, activity session recording / configuration change recording is possible with certain vendors to make them more secure.

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