M04 Q37 Why do you want to leverage 3rd-party external monitoring system?

It is a good idea to use external monitoring system, because this way you can use monitoring functionalities without having to spend time coding them.

External monitoring system usually provides:

Durable persistent storage
Tested way of ingesting massive amount of data
A way to query for data
A way to perform data visualization
Configurable Dashboards
Configurable alerting

Spring Actuator uses Micrometer Application Metrics Facade which integrates with number of external monitoring systems. Provided dependency management and auto-configuration makes it easy to integrate Micrometer into your project.

Spring Boot supports following monitoring systems:

AppOptics
Atlas
Datadog
Dynatrace
Elastic
Ganglia
Graphite
Humio
Influx
JMX
KairosDB
New Relic
Prometheus
SignalFx
Simple (in-memory)
StatsD
Wavefront

Configuring external monitoring system is as easy as adding dependency:

<dependency>
    <groupId>io.micrometer</groupId>
    <artifactId>micrometer-registry-${monitoring-system-name}</artifactId>
</dependency>

You might also need to configure some properties, for example:

management.metrics.export.elastic.host=http://localhost:9200