Ganglia vs Munin: What are the differences?
Ganglia: Scalable distributed monitoring system. 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; Munin: PnP networked resource monitoring tool that can help to answer the what just happened to kill our performance. Munin is a networked resource monitoring tool that can help analyze resource trends and "what just happened to kill our performance?" problems. It is designed to be very plug and play. A default installation provides a lot of graphs with almost no work.
Ganglia and Munin can be categorized as "Monitoring" tools.
Munin is an open source tool with 1.31K GitHub stars and 383 GitHub forks. Here's a link to Munin's open source repository on GitHub.