Conflict resolution for applications

Application streaming comes with a significant side benefit: eliminating application conflicts. The application streaming tools from AppStream, Altiris, and Microsoft separate application-specific support files such as DLLs and libraries from the underlying operating system. Altiris separates just the support files, keeping the applications with the operating system, whereas AppStream and Microsoft keep each app and its support files together in one virtual layer or package.

These programs manage the communication among the layers and the underlying operating environment, so both Windows and its users think they are working on a single environment. By separating each application into its own virtual layer (or package, as some call it), these products prevent software conflicts common with homegrown software and some commercial applications. And user-installed applications can’t conflict with IT-provisioned applications in the virtual layers, says Microsoft’s Grescher.

For example, before adopting SoftGrid, recalls Alamance’s Gerringer, the medical center had to maintain separate servers for ill-behaved apps, forcing users to switch among multiple systems from their terminals. “By summer 2005, the problem got too big to manage anymore the old way,” Gerringer says.

The problem? Different versions of Java used by various specialty health care apps prevented simultaneous usage, as did the embedding of different versions of the Crystal Reports reporting tool in other applications. (If Crystal Reports 4 is running, Crystal 5 cannot run, for example.)

Now that Alamance uses SoftGrid, users get a unified desktop environment, with the ill-behaved apps corralled so they can no longer cause trouble.

The new reality of virtualization

Desktop and application streaming require IT to think differently about tasks that they’ve done for years, notes Neal of Duncan Regional Hospital. “It takes a little more thought in the rollout,” he says. For example, his support staff now has to keep an eye on the blades that serve the desktop environments, because a broken fan can cause them to overheat, knocking out multiple users in one blow. His staff also must monitor disk usage for each blade, because 80GB is shared among three users.

Virtualized desktops can be provisioned to specific client hardware, so a particular call-center terminal always uses the same virtual machine on a specific blade. But they can also be provisioned to specific users, based on user log-in, so the client device running them could be anywhere. That can pose a challenge for setting up access to printers and departmental file servers, depending on how mobile users are, observes Bell’s Quigley.

Quigley notes another issue that can puzzle support staff: Users connecting from home may not get their DNS address resolved properly, so IT tends to assign a fixed IP address to get around that issue. But the Windows virtual machines are rebooted each night to deal with memory leaks, and the IP address for that virtual machine might no longer match what is set up in the remote user’s home system.

Nonetheless, early adopters all agree that these relatively minor issues are far outweighed by the benefits of central administration of fewer desktop images. As IDC’s Humphreys says, “There are some really pragmatic reasons that this is taking off.”