Application streaming creates a virtualized desktop that can be managed centrally, yet offers the speed of local execution. Automated software distribution has been a hot topic in desktop management, but the next big thing is on-demand software delivery. While ASD tools help control desktop support costs by making software installations consistent, the on-demand software-delivery technologies go one step further: They can virtualize the local installation and stream the applications -- and even the operating system -- from a central distribution server in real time.
It creates and stores complete system images on a server and streams portions of the operating system and applications to desktop users at boot-up. "It didn't require a large investment in server infrastructure and provided immediate ROI," .
Application streaming technology takes advantage of the fact that LANs are getting faster -- and that most applications require only a small fraction of the total program code in order to run. The minimum needed can be as little as 10% to 15% .
Once the user is up and running, additional application and operating system components are fetched as needed. After the initial launch of a program, some products allow portions of the applications to reside in a local cache for faster subsequent loads. The result: Applications can be maintained and updated on central servers but run on the end user's local machine. The issue of managing locally installed programs on individual desktops is eliminated.
This concept is not new. But in late 90s such concept is very popular with Novell Netware. Few of my friends are asking alot abt it saying the new technology. But my friends I already did such thing in Late 90s only difference is that now things are much more optimised and in big scale. Ist somthing which I remember I read an add of an bike they mentioned that Big has fins in engine in their advertisiments. But now every one tnow that any air cooled engine required an fis to dissapate the maximum of heat.
Lets take a deeper look on the topic.
Vendors of just-in-time streaming products fall into one of two categories. Companies such as Ardence offer products that stream complete disk images that include the Windows operating system and a predetermined application set. Companies like AppStream Inc. stream only the applications but offer more granular control over application delivery.
Still other vendors, including Softricity Inc. and Stream Theory Inc., take application streaming one step further by creating a self-contained virtual environment in which each streamed application can run. The virtualization layer traps and isolates registry entries, Dynamic Link Libraries (DLL) and other changes the application wants to make to Windows settings. This avoids application conflicts and eliminates the need for administrators to do regression testing and build images for every combination of applications.
Since applications are delivered centrally, software streaming products allow application licenses to be tightly controlled. "The idea is to create an environment where applications can be made available on devices in a very managed, controlled way and then removed from the device so they can be used somewhere else," .Streaming technology lowered desktop support costs by reducing help desk calls resulting from malware problems. "Now, when they get [a virus], they just reboot and get a new image,". One of the vendor an case study says that centralized management also made upgrades easier. A typical upgrade to the company's Avaya Call Center software, which used to take 75 hours to test and roll out, is now completed in about one hour, he says, because fewer images are needed and the software doesn't have to be installed on each machine.
Time Warner's PCs support PXE boot technology, which lets the machines remote-boot directly from the system image that the Ardence server delivers. PCs boot over the Gigabit Ethernet network faster than they did when running locally, and bypassing the local disk drive has saved on support costs. "Eighty percent of our trouble tickets are hard-drive-related," .
The downside, is that building the images used for streaming can be time-consuming currently.
Neoware's Image Manager attempts to reduce the number of images required by creating a virtualization layer that allows a single image to run on different systems. "We have a virtualized driver model that lets the operating system boot regardless of what the hardware is," says Neoware CEO Michael Kantrowitz. It is limited, however, to only those drivers that are built into Windows. Applications with unique drivers require a separate image. With both products, administrators still must create different images for each desired application set.
Speed and Flexibility
"It takes less than a minute before they can use the [updated] applications. That's definitely better than having someone walk around to 2,000 PCs," .
Managing multiple images is impractical at Suncor Energy Services Inc., which has 1,600 applications on some 4,500 PCs. Between 75% and 85% of those applications are now delivered by way of Softricity's SoftGrid server. SoftGrid includes a "sequencer" utility that encapsulates all of the system changes that the application's installation routine makes and places those in a semi-isolated virtual environment on the PC, along with the installed application image. Applications are delivered automatically based on policies set in Active Directory and are removed when the session ends.
Some useful quotes
Software updates that used to take a month to deploy are now completed in one day. Weiszhaar doesn't need to first perform regression testing on the application, produce a distribution package and test it. "Within five minutes we can deploy it to every single person in the company," he says.
Stream Theory claims to offer application environment virtualization that's more flexible. AppExpress lets the administrator specify which DLLs or other application components can be virtualized and which need to talk to one another, says Chief Technology Officer Arthur Hitomi. The software won't, however, allow incompatible versions of an Oracle or Office application to run simultaneously, as Soft-Grid does.
"We had to silo-out hardware due to different versions of Office or Oracle," says Weiszhaar. SoftGrid eliminated the conflicts, and Weiszhaar was then able to distribute those applications across more servers.
Deployments of new applications via MetaFrame are also easier. "We can take your new application that we've never run before, put it on a server with production applications running, and we don't have to worry about it breaking anything," O'Brien says.
While approaches to application streaming vary, in the end all vendors attempt to deliver applications to the end device in a managed, secure way, says IDC's Kusnetzky. While SoftGrid's offering is the most mature, administrators will need to examine each approach carefully before making a decision, he says. "There may be six or seven ways to do it. That's got to be very confusing for an organization trying to decide what is the best solution for their needs."