Enable tracing with Jaeger on Sentinel by installing the `opennms-core-tracing-jaeger` feature.

NOTE: Configurations has to be made in the `etc` directory relative to the Sentinel home directory.
      Depending on your operating system the home directory is in `/opt/sentinel`.

.Create a file to load the tracing feature on startup
[source, console]
----
sudo vi etc/featuresBoot.d/jaeger.boot
----

.Add the Jaeger feature and save the file
[source, jaeger.boot]
----
opennms-core-tracing-jaeger
----

NOTE: Uninstalling the `opennms-core-tracing-jaeger` feature at runtime is not yet supported.
      To disable tracing with Jaeger, remove the reference from the features boot file and restart Sentinel.

.Create a configuration file for tracing settings
[source, console]
----
sudo vi etc/custom.system.properties
----

.Add configuration properties for tracing with Jaeger
[source, jaeger.properties]
----
JAEGER_AGENT_HOST=http://localhost:14268/api/traces<1>
----

<1> Replace the `http://localhost:14268` with your Jaeger instance where you collect the tracing information

TIP: Available configuration options are listed in the link:https://github.com/jaegertracing/jaeger-client-java/blob/master/jaeger-core/README.md[Jaeger Core Readme].

NOTE: The Jaeger service name is the `Instance-ID` from Sentinel.

.Restart Sentinel to apply the changes
[source, console]
----
sudo systemctl restart sentinel
----
