[role="xpack"]
[[how-monitoring-works]]
== How monitoring works
++++
<titleabbrev>How it works</titleabbrev>
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Each monitored {stack} component is considered unique in the cluster based on
its persistent UUID, which is written to the <<path-settings,`path.data`>>
directory when the node or instance starts.

Monitoring documents are just ordinary JSON documents built by monitoring each
{stack} component at a specified collection interval. If you want to alter how
these documents are structured or stored, refer to <<config-monitoring-indices>>.

You can use {agent} or {metricbeat} to collect monitoring data and to ship it
directly to the monitoring cluster.

To learn how to collect monitoring data, refer to:

* One of the following topics depending on how you want to collect monitoring
data from {es}:
** <<configuring-elastic-agent>>: Uses a single agent to
gather logs and metrics. Can be managed from a central location in {fleet}.
** <<configuring-metricbeat>>: Uses a lightweight {beats}
shipper to gather metrics. May be preferred if you have an existing investment
in {beats} or are not yet ready to use {agent}.
** <<collecting-monitoring-data>>: Uses internal exporters to
gather metrics. Not recommended. If you have previously configured legacy
collection methods, you should migrate to using {agent} or {metricbeat}.
* {kibana-ref}/xpack-monitoring.html[Monitoring {kib}]
* {logstash-ref}/configuring-logstash.html[Monitoring {ls}]
* {enterprise-search-ref}/monitoring.html[Monitoring {ents}]
* Monitoring {beats}:
** {auditbeat-ref}/monitoring.html[{auditbeat}]
** {filebeat-ref}/monitoring.html[{filebeat}]
** {heartbeat-ref}/monitoring.html[{heartbeat}]
** {metricbeat-ref}/monitoring.html[{metricbeat}]
** {packetbeat-ref}/monitoring.html[{packetbeat}]
** {winlogbeat-ref}/monitoring.html[{winlogbeat}]
* {apm-guide-ref}/monitor-apm.html[Monitoring APM Server]
* {fleet-guide}/monitor-elastic-agent.html[Monitoring {agent}s]
{fleet}-managed agents) or
{fleet-guide}/elastic-agent-monitoring-configuration.html[Configure monitoring for standalone {agent}s]