April 27, 2010
    TeamQuest engineer Scott Johnson wanted the audience to walk away with the following main points from his presentation:
    • While measuring application response time can be a challenge, there are some reasonable options for passive data collection.
    • A fortuitous side effect of some response time monitoring agents is additional data that can be used for application trouble shooting and business intelligence.
    • Application measurements can be used to enhance capacity models.
    Johnson also noted that transaction rate and response time information are very valuable for monitoring service level agreements. In the world of Unix, Linux, and Windows, there is no standard transaction monitor for applications. For those that grew up in the mainframe world with proprietary transaction monitors, this situation is a bit unsettling. However, several approaches have been developed to address certain classes of applications.One approach for web-based applications is to use synthetic transactions and response time "robots" to initiate and measure these transactions. This approach is called active measurement since it initiates a small artificial load on the application in order to obtain measurement data. This approach provides reasonable indicators of application availability and network latency.Another approach is to instrument the application and then make the response time information available, perhaps through an application log file. Also, the technology used in web applications provides the possibility for web server log file analysis and TCP packet sniffing. These last approaches are usually called passive monitoring since they add no transaction load to the application. The advantage of passive monitoring is the potential to understand the actual rate of application activity and the actual user experience.Thanks to Scott for this post.