name: Nagios Vocabulary
description: |
  Domain vocabulary for the Nagios family of monitoring tools. Captures the
  canonical concepts shared across Nagios Core, Nagios XI, NCPA, NRPE, NSCA,
  NRDP and related Nagios Enterprises projects.
version: '0.1'
terms:
  Host:
    definition: A monitored network entity (server, switch, router, sensor) identified by `host_name` and reachable at an `address`.
    aliases: [Node]
  Service:
    definition: A monitored function or metric on a host (PING, HTTP, CPU). Tied to one host via `host_name` + `service_description`.
  HostGroup:
    definition: A named collection of hosts used for assignment and reporting.
  ServiceGroup:
    definition: A named collection of services used for assignment and reporting.
  Contact:
    definition: A notification recipient with one or more notification methods.
  ContactGroup:
    definition: A named collection of contacts.
  CheckCommand:
    definition: A reusable command definition that wraps a Nagios plugin invocation.
  Plugin:
    definition: An executable returning a Nagios exit code (0/1/2/3) and a stdout summary plus optional `| perfdata`.
  ActiveCheck:
    definition: A check executed by Nagios on a schedule against a host/service.
  PassiveCheck:
    definition: A check result submitted *to* Nagios by an external source (via NSCA, NRDP, NCPA push, or external command pipe).
  State:
    definition: Current evaluated state. Hosts use UP/DOWN/UNREACHABLE; services use OK/WARNING/CRITICAL/UNKNOWN.
  StateType:
    definition: SOFT (transitioning) or HARD (confirmed after max_check_attempts).
  Downtime:
    definition: A scheduled window during which notifications are suppressed for a host or service.
  EventHandler:
    definition: A script triggered on state changes to perform remediation or escalation.
  Notification:
    definition: An alert sent to contacts when a host/service changes state, honoring time periods and escalation rules.
  TimePeriod:
    definition: A named schedule defining when checks or notifications may occur.
  Escalation:
    definition: A rule that re-notifies different contacts after a configurable number of notifications.
  Flapping:
    definition: Rapid state oscillation detected by Nagios to suppress alert noise.
  Perfdata:
    definition: Optional pipe-delimited performance metrics appended to plugin output, parsed by graphing back ends.
  NEB:
    definition: Nagios Event Broker — Nagios Core's in-process module loader for extensions (mod-gearman, NDOUtils, NSCA helpers).
  NCPA:
    definition: Nagios Cross-Platform Agent — Python/Shell-based monitoring agent for Linux/Windows/macOS exposing an HTTPS API on port 5693.
  NRPE:
    definition: Nagios Remote Plugin Executor — daemon that runs Nagios plugins on a remote host on TCP port 5666.
  NSCA:
    definition: Nagios Service Check Acceptor — encrypted binary daemon (TCP 5667) for submitting passive check results.
  NRDP:
    definition: Nagios Remote Data Processor — PHP-based HTTP collector accepting XML/JSON passive check submissions.
  ApiKey:
    definition: Per-user token used to authenticate Nagios XI REST API calls via the `apikey` parameter.
  ApplyConfig:
    definition: Operation that validates pending configuration changes and restarts Nagios Core.
tags:
  - Monitoring
  - Infrastructure Monitoring
  - Network Monitoring
  - Open Source
  - IT Operations
  - Alerting
  - Observability
  - Nagios Core
  - Nagios XI
  - NCPA
  - NRPE
  - NSCA
  - NRDP