When we started Blue Gecko, we relied heavily on free, open-source software because a) as a startup we couldn't afford most commercial solutions, and b) as DBAs we found most commercial solutions too generic and too difficult to adapt to specific customer monitoring challenges. We adopted Nagios as a monitoring framework not only because it was freely available, but because the monitoring framework was so technology agnostic: We could write a plug-in to do anything we wanted and as long as we followed the API, we could monitor anything in a nice, clean, consistent manner.

Monocle evolved out of that use of open sourced software and is primarily PL/SQL code running as scheduled Oracle jobs. These monitors look for and report on various issues that exist within an Oracle database. In our first release we've chosen to include a Nagios plug-in. 

Monocle is a monitoring system that can be integrated with multiple alerting mechanisms by Blue Gecko or on-site staff.

In concert with the monitoring components of Monocle we have developed several utilities and reports to help with the day-to-day management of an Oracle database.