Jun 112010

In the performance management area, I have talked about network and device performance management. I should also mention the application performance management to complete the picture.

Application performance managers(APMs) track how much time an application is available and how well it meets the expected functionality. APMs have different types: Transactional Monitors, User Monitors, Application Server Monitors and Database Monitoes.

Transactional Monitors:

Typically, if you want to monitor an application, you should first determine on the use cases that will be implemented by the monitor. Use cases are a set of activities or business processes that the monitor should perform. A use case example could be:

– Open the application URL
– Enter username and password and press submit
– After successful login, click on the report 1 and wait for the report to be displayed.
– Logoff

APMs run these activities (transactions) one by one and wrote down the response times. They also check if any errors occurred during the process.

User Monitors:

Most of the APMs simulate the user behavior but some of them also “sniff” the user actions. An agent program that is installed on the user machine tracks the user actions in the form of KPIs. One of the most important KPI is the “think time” which represents the end-user’s thinking period. (between an action’s result and the next action.)

Application Server Monitors:

APMs are also able to track application server performances such as Websphere, Tomcat etc. These APMs report the application server’s performance and monitor the process stacks to find the most time consuming method calls. These statistics are extremely important if you are dealing with an in-house application and trying to pinpoint a performance degradation points.

Database Monitors:

Database specific APMs monitor the well-known databases( Oracle, DB2, MS SQL Server etc.) and their performances.

APM statistics should be correlated along with the server (OS Level) statistics. An end-to-end view will also require the network related statistics and customer experience management statistics(from active probes). At the end of each monitoring, a set of KPIs are exposed. These KPIs are fed to performance management systems and SQM systems to be further analyzed.