// 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 when you are enabling tracing for Kafka components or initializing a tracer for Kafka clients.

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

The following tables describe the key environment variables for setting up a tracer. 

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

|Property
|Required
|Description

|OTEL_SERVICE_NAME
|Yes
|The name of the Jaeger tracing service for OpenTelemetry.

|OTEL_EXPORTER_JAEGER_ENDPOINT
|Yes
|The exporter used for tracing.

|OTEL_TRACES_EXPORTER
|Yes
|The exporter used for tracing.
Set to `otlp` by default. If using Jaeger tracing, you need to set this environment variable as `jaeger`.
If you are using another tracing implementation, xref:proc-enabling-tracing-type-{context}[specify the exporter used].


|===

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

|Property
|Required
|Description

m|JAEGER_SERVICE_NAME
|Yes
|The name of the Jaeger tracer service.

m|JAEGER_AGENT_HOST
|No
|The hostname for communicating with the `jaeger-agent` through the User Datagram Protocol (UDP).

m|JAEGER_AGENT_PORT
|No
|The port used for communicating with the `jaeger-agent` through UDP.

|===