Here is an ONLamp article that is interesting. “By recording performance metrics, web server administrators can have a historical record of how the server handled incoming HTTP requests. This article expands on that concept by adding a couple of logging directives and recording the logging data directly in a MySQL database.”
QueryCommander is a Open Source Query Analyzer that you can use to work with the following Databases.
SourceForge.net: Project Info - Enterprise Monitoring, Windows Systems
Centrally monitor eventlogs, no agents needed; Send alerts to different people on different events; Integrated with ticket tracking system; Forward events to syslogd; Archive events into MYSQL/MSSQL; Web interface to search for events;
Cerberus Helpdesk - We use cerburus at work and have been pretty happy with it.
RT: Request Tracker - I am still looking into RT since I have found some intresting features for it.
The one and the only RRDtool