Ensuring application performance requires two monitoring approaches: Application Performance Monitoring and Infrastructure Monitoring.
Application Performance Monitoring is the monitoring of the response time of both end-user transactions and service sub-components (e.g., response time of a database call or web service). It measures the quality of the “outputs” of the application and its moving parts.
Infrastructure Monitoring is the monitoring of the availability and performance of the application delivery chain’s infrastructure components. It measures the availability of the “inputs” to the application, without which the “outputs” will suffer.