What is the difference between rules and threshold if my main goal is generate Alarm when metric will be above or below threshold? What's have priority compared with each other.
A rule is what runs against the metrics in the repository. A threshold is a variable that a condition of the rule checks the metric against, and an alarm is what is created if that condition is true. Plenty of information in the documentation: https://support.quest.com/technical-documents/foglight/5.7.5/administration-and-configuration-guide/8#TOPIC-453863