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Configure the Java agent for Splunk Observability Cloud 🔗

You can configure the Java agent from the Splunk Distribution of OpenTelemetry Java to suit most of your instrumentation needs. In most cases, modifying the basic configuration is enough to get started. More advanced settings are also available.

The following sections describe all available settings for configuring the Java Virtual Machine (JVM) agent, including options for activating new features that are unique to the Splunk Distribution of OpenTelemetry Java.

Configuration methods 🔗

You can change the agent settings in two ways:

  • Set an environment variable. For example:

    export OTEL_SERVICE_NAME=my-java-app

  • Add a system property as runtime parameter. For example:

    java -javaagent:./splunk-otel-javaagent.jar \
-Dotel.service.name=<my-java-app> \
-jar <myapp>.jar

Environment variables are the preferred way of configuring OpenTelemetry agents. System properties, if specified, override existing environment variables.

General settings 🔗

The following settings are specific to the Splunk Distribution of OpenTelemetry Java:

Example of trace sampling 🔗

The following example shows how to use the rules traces sampler to exclude the /healthcheck endpoint from monitoring:

export OTEL_TRACES_SAMPLER=rules
export OTEL_TRACES_SAMPLER_ARG=drop=/healthcheck;fallback=parentbased_always_on

All requests to downstream services that happen as a consequence of calling an excluded endpoint are also excluded.

Considerations on trace propagation 🔗

For backward compatibility with older versions of the Splunk Distribution of OpenTelemetry Java or the SignalFx Java Agent, use the b3multi trace propagator:

export OTEL_PROPAGATORS=b3multi

Instrumentation configuration 🔗

The following settings control the instrumentation, including tracing and :

Exporters configuration 🔗

The following settings control trace exporters and their endpoints:

The Splunk Distribution of OpenTelemetry Java uses the OTLP http/protobuf span exporter by default. To send data directly to Splunk Observability Cloud, see Send data directly to Splunk Observability Cloud.

Java settings for AlwaysOn Profiling 🔗

The following settings control the AlwaysOn Profiling feature for the Java agent:

For more information on AlwaysOn Profiling, see Introduction to AlwaysOn Profiling for Splunk APM.

Server trace information 🔗

To connect Real User Monitoring (RUM) requests from mobile and web applications with server trace data, trace response headers are activated by default. The instrumentation adds the following response headers to HTTP responses:

Access-Control-Expose-Headers: Server-Timing
Server-Timing: traceparent;desc="00-<serverTraceId>-<serverSpanId>-01"

The Server-Timing header contains the traceId and spanId parameters in traceparent format. For more information, see the Server-Timing and traceparent documentation on the W3C website.

The following server frameworks and libraries add Server-Timing information:

  • Servlet API versions 2.2 to 4.X.

  • Netty versions 3.8 to 4.0.

Note

If you need to deactivate trace response headers, set SPLUNK_TRACE_RESPONSE_HEADER_ENABLED to false.

Other settings 🔗

Environment variable

Description

OTEL_JAVAAGENT_ENABLED

Globally activates the Java agent automatic instrumentation. The default value is true. Useful for deactivating automatic discovery in testing scenarios or pipelines.

System property: otel.javaagent.enabled.

This page was last updated on May 16, 2024.