The Munin master

Role

The munin master is responsible for gathering data from munin nodes. It stores this data in RRD, and graphs them on request.

The following components are part of munin-master:

munin-cron runs munin-graph, munin-html, munin-limits and munin-update.
munin-update is run by munin-cron. It is the munin data collector, and it fetches data from munin nodes <munin-node>, which is then stored in RRD files.
munin-graph is run by munin-cron. It generates graphs in PNG format from the RRD files. See also munin-cgi-graph.
munin-limits is run by munin-cron. It notifies any configured contacts if a value moves between "ok", "warn" or "crit". Munin is commonly used in combination with Nagios, which is then configured as a contact.
munin-html is run by munin-cron. It generates HTML pages. See also munin-cgi-html.
munin-cgi-graph is run by a web server. If graph_strategy is set to "cgi", munin-cron will not run munin-graph, and assumes that the web server runs munin-cgi-graph instead.
munin-cgi-html is run by a web server. If html_strategy is set to "cgi", munin-cron will not run munin-html, and assumes that the web server runs munin-cgi-html instead.

The munin master has its primary configuration file at /etc/munin/munin.conf <munin.conf>.