You know those familiar CPU and disk usage meters that have been so much a part of application performance management? Although still important, they are no longer the only game in town when it comes to understanding enterprise distributed system behavior. According to Bernd Harzog, CEO and founder of APMExperts, the end-user experience is rapidly becoming a more important arbiter of system performance.
Moreover, as virtualization technology on servers becomes more widespread, established ways of doing performance management are further challenged, Harzog said. Recently, Harzog took part in a webcast on SearchSoftwareQuality.com, "How to maintain high application performance," covering application performance management trends.
The traditional approach to performance management relied primarily on monitoring how applications use CPU, memory and network resources. Resource monitoring agents placed on servers gathered the key data. But measuring response time -- in effect, the end-user perspective -- is becoming a better measure.
The lineage of much application performance management technology goes back to the day when the mainframe, not the user, was king.
"Application performance management was a set of products and a discipline around measuring the resources," said Harzog. But, often, when the user or the business unit has called up and said "the application is too slow," the view of those server agents showed that the system was okay. That leads to a mismatch between the expectations of the user and the expectations of IT, Harzog indicated during the course of his webcast.
"Over time a new definition of application performance management has evolved around response time and around user experience," Harzog said. "This has happened because, with Web-based applications, it was possible to do more easily than it was in the past and [because] IT has come under unrelenting pressure from the business to deliver applications that actually perform in the eyes of the user in a consistent manner."
Among the tool types playing a role in measuring user experience, he said, are HTTP appliances, synthetic transaction scripts and end-user PC-based agents.
What happens as virtualization comes online big time? In virtualization, clusters of servers that each used to be their own physical device are combined.
"What happens then is the operating system that runs inside those servers is running in one of many guest OSes on a physical host," said Harzog. "The OS does not know it is running in a guest, nor do the monitors know they are sharing a clock and CPU with other applications," he added.
That spells trouble for server-based agents.
Time-slicing the clocks breaks management agents, said Harzog, who noted that companies are presently working on tools to meet this new challenge.