This module is designed to allow Munin reporting of Drupal-related information.

Munin itself is an Open Source monitoring solution able to track just about any time-series information using the RRDtool graphing package originally made popular by the MRTG monitoring system.

It is generally used by system and network administrators for low-level technical information, but the Munin API module enables it to go beyond such system-level monitoring, to include Drupal-level, or even business-level monitoring.

Bundled graph providers

Munin API is provided with a number of graph providers by default, each of them providing several graphs

• drupal_apc
  • APC memory use: allocated, used
  • APC entries: hits, misses, insertions, entries, deleted entries.
  • APC uptime
  • Due to APC architecture, this plugin can only work if the module is running in normal Drupal mode, not from a CLI SAPI, as will happen when using a Drush plugin to query the Munin API module. Other bundled graph providers do not have this limitation.
• drupal_core
  • core content: nodes (published vs unpublished), comments (published vs unpublished)
  • core taxonomy: vocabularies, terms
  • core users: users (active vs blocked), sessions (anonymous vs logged)
• drupal_munin
  • This provider is wired into the Munin API module itself. It periodically checks whether Munin came to gets its data, making it able to warn in case of anomalous Munin probing like missed probes or probes coming in too fast.

Non-bundled graph providers

The Munin API module has been designed to be extended by custom graph providers, created for the specific needs of any specific site.

New graph providers can be added by just implementing two hooks:

• hook_munin_api_info() to declare a graph provider
• hook_munin_api_fetch($graph_name) to return the data for a specific graph

Graph providers vs Munin plugins

Technically, Munin API serves data from its graph providers as just one Munin-level multiple graph plugin.

A default Munin-level plugin is provided in the plugins/ directory. Most sites will likely expand on this sample.