Solving the Thorny Issue of QOS in Virtualized Applications

By Chris Talbot

Porting existing applications that reside on a traditional physical infrastructure to a virtualized environment in the cloud sounds like a great idea, but the reality is that shifting apps to the cloud may come with a decrease in application performance. Ensuring quality of service of those applications is important to keep them running at expected levels, which in turn keeps productivity up.
According to Zohar Gilad, executive vice president of Precise Software, the key component to ensuring quality of service to virtualized applications is automation. The most common applications being ported to the cloud right now are second and third tier apps, the non-mission critical business apps like web servers, print servers, etc. Making those applications virtual will offer the business cost savings and more agility because it’s easy to provision virtual servers, but if those applications aren’t functioning at previous levels of efficiency, was it really worth it to make the move to a virtual infrastructure?

"What happens when you move from physical to virtual infrastructure [is] most of the old problems that presented applications to scale gracefully has now gone away," Gilad said. "All the old problems are still here. As with any new computing platform, you have a new set of issues."

There are three main problems associated with applications in virtualized environments:

  1. The problems of a traditional infrastructure don’t suddenly go away.
  2. Degradation of quality of service during and after the transition to virtualization.
  3. Inter-application shared resource contention can degrade performance.

Michelle Warren, president of MW Research and Consulting, degradation of application performance when software is moved to virtualized environments is something that organizations are worried about right now.

"And the reason it depends is software is really tricky, and to be able to do one thing and one program, users tend to think we can do it in another program," Warren said. "There’s this belief that everything’s straightforward, but in reality, in the background it’s very complicated. They’re complex environments.

The slightest change reaches down through the application, so porting something into a virtualized environment is just fraught with the ability to add complexities and change the way it looks, change the way users interact with it and the way it interacts with other programs."

The virtualization layer means it’s harder to isolate problems than if the application was hosted in a traditional manner, Gilad said. The old problems don’t go away, but virtualization brings with it a new set of problems, as well. If something doesn’t function right in a traditional IT environment, the problem will be there until the IT technician gets around to fixing it, but in a virtual world, the virtual machine that is being problematic may disappear long before the technician has time to look at the problem, he said.

The solution is application performance management technology, which is Precise Software’s specialty. Precise provides automated application performance management with agents that enable the software to see what’s going on and suggest potential fixes as problems pop up.

Application performance management tools provide a way to monitor applications and provide reports even after the virtual machine is no longer in use, Gilad said. The tools can rewind time, so to speak, so IT professionals can view decommissioned virtual machines and see what was going on when users experienced problems.

With information collected by application performance management tools, IT professionals can view every transaction the application processed and isolate a problem. Being able to isolate problems on decommissioned virtual machines will enable IT to provide a higher level of performance, Gilad said.

Some of the cost savings from virtualization are gained through applications sharing resources, but that can have a negative performance impact on the apps, he said. Application performance management software can give visibility into the different applications depending on shared databases and services, and then show how they conflict with each other.

For channel partners, this presents an opportunity not just to make margin on the sale of application performance management software, but also to provide customers with professional services. Gilad noted that providing performance management as a service as an MSP is a great opportunity for partners.

Warren agreed there is a huge opportunity for partners to help their customers because they understand the complexities of application performance and the different environments that software runs in. That’s a value-add they can offer their customers. Many partners specialize in tweaking software to make sure it’ll run properly in the specific environment the customer needs to run it in.


This article was originally published on 2010-11-22