Ganglia – Cloud Monitoring Tool
Ganglia is a monitor tool for high performance computing systems such as Private Clouds, Public Clouds, clusters, and grids. The ganglia system contains 1) two unique daemons 2) a PHP-based web front end, and 3) other small programs. Gmond, multi threaded daemon runs on each node to monitor changes in host state, announce applicable changes, listen to the state of all ganglia nodes via a unicast or multicast channel based on installation, and respond to requests. Ganglia Meta Daemon at regular intervals polls a collection of data sources, parses the XML, saves all metrics to round-robin databases and exports the aggregated XML. The Ganglia web front end is written in the PHP and uses graphs generated by gmetad provides collected information e.g. CPU utilization for past day, week, month, or year.
Multicast mode is the default setting in Ganglia installation and is the simplest to setup which provides redundancy. Public Cloud Environments such as Amazon’s AWS EC2 do not support multicast, so unicast mode installation is the only setup option available. Eucalyptus is open source product for building AWS compatible private clouds; its open-source version does not provide built in monitoring but that can be achieved with Ganglia. Eucalyptus source package includes scripts which may be used with third party tools such as Ganglia to enable Eucalyptus-specific monitoring on predefined number of hosts.