// Module included in the following assemblies:
//
// assembly-distributed tracing.adoc

[id='ref-tracing-environment-variables-{context}']
= Environment variables for tracing

[role="_abstract"]
Use environment variables to enable tracing for Kafka components or to initialize a tracer for Kafka clients.

Tracing environment variables are subject to change. 
For the latest information, see the {OpenTelemetryDocs}.

The following table describes the key environment variables for setting up tracing with OpenTelemetry. 

.OpenTelemetry environment variables
[cols="2m,1,2",options="header"]
|===

|Property
|Required
|Description

|OTEL_SERVICE_NAME
|Yes
|The name of the tracing service for OpenTelemetry, such as OTLP or Jaeger.

|OTEL_EXPORTER_OTLP_ENDPOINT
|Yes (if using OTLP exporter)
|The OTLP endpoint for exporting trace data to the tracing system.
For Jaeger tracing, specify the `OTEL_EXPORTER_JAEGER_ENDPOINT`.
For other tracing systems, xref:proc-enabling-tracing-type-{context}[specify the appropriate endpoint]. 

|OTEL_TRACES_EXPORTER
|No (unless using a non-OTLP exporter)
|The exporter used for tracing. 
The default is `otlp`, which does not need to be specified. 
For Jaeger tracing, set this variable to `jaeger`. 
For other tracing systems, xref:proc-enabling-tracing-type-{context}[specify the appropriate exporter].

|OTEL_EXPORTER_OTLP_CERTIFICATE
|No (required if using TLS with OTLP)
|The path to the file containing trusted certificates for TLS authentication.
Required to secure communication between Kafka components and the OpenTelemetry endpoint when using TLS with the `otlp` exporter.

|===