Beats are lightweight data shippers. You install a Beat on your server to collect certain data and send it either to Logstash or directly to Elasticsearch. Icingabeat is a Beat that fetches data from the Icinga 2 API. It collects events generated during the monitoring process. An event can be a check result received from a plugin, a notification sent to a user, a downtime triggered through Icinga Web 2 or many other things.
Logstash Output Plugin
Logstash is a data processing pipeline. Logs and events are either actively collected or received from third party resources like Syslog or the Elastic Beats. The Icinga Output Plugin aims to build a bridge between your logging management and your monitoring. It can run various actions on your Icinga server by calling the Icinga API.