The most challenging and cpu intesive process in monitoring is the correlation of events. Think of a network with 128,000 events per second *. This is not to uncommmen just look at NMS, firewalls and other network components. These events are not all critical or severity one issues, most just informational. The problem is filtering, correlating and escalating the event that brings your service down. Just as important are undetected security breaches by filtering network events.

To correlate the high volume of these events or to detect security issues can be a challenge. Can your 1, 2 or even 10 server in-house hosted monitoring environment process all network, transaction, application, database and systems events? Do you filter 90% or more of the network events in your environment?

Leveraging monitoring-as-a-service infrastructures designed for cloud computing to process and corelate events real-time, may be an alternative to your open source canned solutions. Typically opensource solutions require your businesses resources for patches, problems and fixes. If your core business process is not monitoring why spend so much time and energy maintaining cool GUI software?