X-Pack monitoring in Kibana serves two separate purposes:

  1. To visualize monitoring data from across the Elastic Stack. You can view health and performance data for Elasticsearch, Logstash, and Beats in real time, as well as analyze past performance.
  2. To monitor Kibana itself and route that data to the monitoring cluster.

If you enable X-Pack monitoring across the Elastic Stack, a monitoring agent runs on each Elasticsearch node, Logstash node, Kibana instance, and Beat to collect and index metrics. Each node and instance is considered unique based on its persistent UUID, which is written to the directory when the node or instance starts.

For more information, see Configuring monitoring and Monitoring the Elastic Stack.