Alert definitions define when to trigger an alert and for which entity.
Python expression defining the "threshold" when to trigger an alert. See :ref:`alert-condition`.
Python expression defining the value of a check. See :ref:`check-commands`.
A check definition provides a source of data for alerts to monitor. See :ref:`check-definitions`
A dashboard is the main monitoring page of ZMON and consists of widgets and the list of active alerts.
In ZMON, downtime refers to a period of time where certain alerts/entities should not be triggered.
One use case for downtimes are scheduled maintenance works. See :ref:`downtimes`
Entities are "objects" to be monitored. Entities can be hosts, Zomcat instances, but they can also be more abstract things like app domains.
A simple markup language that can mostly pass for plain text. There's an `introduction <http://daringfireball.net/projects/markdown/basics>`_ and a `syntax reference <http://daringfireball.net/projects/markdown/syntax>`_ on its official page.
Alert definition's time period can restrict its active alerting to certain time frames. This allows for alerts to be active e.g. only during work hours.
Not actually Yet Another Markup Language. A powerful but succinct data interchange format. This document should be sufficient to learn how to use YAML in ZMON. In case it isn't, the `Wikipedia entry on YAML <http://en.wikipedia.org/wiki/Yaml>`_ is actually slightly more useful that the `official documentation <http://yaml.org/spec/1.1/#id857168>`_.
Note that YAML is a strict superset of :term:`JSON`. That is, wherever YAML is required, JSON can be used instead.