Severity of the notification. emergency: A panic condition - notify all tech staff on call. alert: Should be corrected immediately - notify staff who can fix the problem - e.g. drive down alert. critical: Should be corrected immediately. Indicates failure in a primary system - fix CRITICAL problems before ALERT error: Non-urgent failures - these should be relayed to developers or admins - each item must be resolved within a given time. warning: Warning messages - not an error, but indication that an error will occur if action is not taken - e.g. cluster capacity is 70% used - each item must be resolved within a given time. notice: Events that are unusual but not error conditions - might be summarized in an email to developers or admins to spot potential problems - no immediate action required. informational: Normal operational messages - may be harvested for reporting, measuring throughput, etc - no action required. debug: Info useful to developers for debugging the application - not useful during operations.