Scalable, distributed monitoring system for high-performance computing
Ganglia is a scalable distributed monitoring system for high-performance computing systems such as clusters and Grids. It is based on a hierarchical design targeted at federations of clusters. Supports clusters up to 2000 nodes in size.
WatchTower is a cloud servermonitoring and management tool
WatchTower is a cloud servermonitoring and management tool. This is actually a suite of tools that includes a dashboard and associated RESTful web services required for managing the servers and services. The dashboard uses PHP/MySQL (requires php5+), html, and css. It's all open source and very easy to work with and make changes. The client I'm using is included and is written in python.