RUE is intended to be used as a general, local or remote, monitoring tool for any Java based server such as Tomcat, Tyrex, Enhydra, JBoss, JOnAS, etc. RUE is written in 100% Java, and features pluggable samplers and sensors, data visualization plug-ins, configurable data history, output of HTML reports, a standard AWT GUI, JNDI-based sensor lookups, and a simple API for pooling, aggregation, and averaging.
Log watcher is a PHP class that polls log files and takes newly added lines to send them to a given watcher email address. Although this class can be used to poll any type of log files, it was developed with the intention to overcome a limitation of the PHP error trapping system that is not able to capture certain types of errors during script execution, like script parsing errors or form file uploading failures. It is meant to be used from cron-like task schedulers to poll log files regularly. The email notification message can be composed from text templates. The message delivery function can be replaced by custom functions like the urgent mail function that can be faster for delivering critical messages.
RRDutil is a a tool to collect statistics (typically every 5 minutes) from multiple servers, store the values in RRD databases (using RRDtool), and plot out pretty graphs to a Web server on demand. The graph types shown include CPU, memory, disk (space and I/O), Apache, MySQL queries and query types, email, Web hits, and more.