HDDS-14961. Introduce configuration for tracing

[sravani-revuri]

What changes were proposed in this pull request?

Currently, OpenTelemetry tracing in TracingUtil relies on environment variables OTEL_EXPORTER_OTLP_ENDPOINT, OTEL_TRACES_SAMPLER_ARG, and OTEL_SPAN_SAMPLING_ARG. which cannot be updated dynamically.
Moving these to the below configs to enable dynamic update.

OTEL_EXPORTER_OTLP_ENDPOINT → ozone.tracing.endpoint
OTEL_TRACES_SAMPLER_ARG → ozone.tracing.sampler
OTEL_SPAN_SAMPLING_ARG → ozone.tracing.span.sampling
Update hdds.tracing.enabled to ozone.tracing.enabled to align with the new naming convention.

What is the link to the Apache JIRA

https://issues.apache.org/jira/browse/HDDS-14961

How was this patch tested?

Manual Testing and existing test cases.

Valid case:

1) Changing ozone.tracing.sample and ozone.tracing.span.sampling:

configs:

OZONE-SITE.XML_ozone.tracing.enabled=true
OZONE-SITE.XML_ozone.tracing.endpoint=http://jaeger:4317
OZONE-SITE.XML_ozone.tracing.sampler=0.5
OZONE-SITE.XML_ozone.tracing.span.sampling=createKey:0.5

Output:

2 traces when command is run 4 times

span level sampling for command:

ozone freon rk --numOfVolumes=1 --numOfBuckets=2 --numOfKeys=2

2) Changing tracing.endpoint

configs:

OZONE-SITE.XML_ozone.tracing.enabled=true
OZONE-SITE.XML_ozone.tracing.endpoint=http://jaeger:4319

Output:

Invalid case:

1) giving non decimal value to ozone.tracing.sample

configs:

OZONE-SITE.XML_ozone.tracing.enabled=true
OZONE-SITE.XML_ozone.tracing.endpoint=http://jaeger:4317
OZONE-SITE.XML_ozone.tracing.sampler=abc

Output:

ozone freon rk --numOfVolumes=1 --numOfBuckets=1 --numOfKeys=2
2026-04-02 06:58:34,974 [main] WARN tracing.TracingUtil: Invalid value for ozone.tracing.sampler: 'abc'. Falling back to default: 1.0
java.lang.NumberFormatException: For input string: "abc"

2) giving wrong values to ozone.tracing.sample and ozone.tracing.span.sampling

configs:

OZONE-SITE.XML_ozone.tracing.enabled=true
OZONE-SITE.XML_ozone.tracing.endpoint=http://jaeger:4317
OZONE-SITE.XML_ozone.tracing.sampler=-0.5
OZONE-SITE.XML_ozone.tracing.span.sampling=createKey:-0.5

Output:

ozone freon rk --numOfVolumes=2 --numOfBuckets=4 --numOfKeys=1
2026-04-02 06:07:50,708 [main] INFO tracing.TracingUtil: Sampling Trace Config = '-0.5'
2026-04-02 06:07:50,708 [main] INFO tracing.TracingUtil: Sampling Span Config = 'createKey:-0.5'
2026-04-02 06:07:50,708 [main] WARN tracing.TracingUtil: rate for span 'createKey' is 0 or less, ignoring sample configuration
2026-04-02 06:07:50,774 [main] ERROR tracing.TracingUtil: Failed to initialize tracing
java.lang.IllegalArgumentException: ratio must be in range [0.0, 1.0]

[sravani-revuri]

@sumitagrawl could you please review this.

[adoroszlai]

Thanks @sravani-revuri for working on this.

• It would be nice if you could add a new TracingConfig class to group tracing-related configuration. That way config keys, values and logic would be in a single class, instead of scattered in 3 different files. (See OmConfig for example. (Keys and Defaults nested classes are not needed.)) This will also make it easier to enable dynamic reconfiguration in the follow-up.
  

  ozone/hadoop-ozone/common/src/main/java/org/apache/hadoop/ozone/om/OmConfig.java

  Lines 36 to 37 in 5e009a3

  	@ConfigGroup(prefix = "ozone.om")
  	public class OmConfig extends ReconfigurableConfig {

• We should still pick up values from environment variables if config is not set. Priority:

  1. config
  2. environment
  3. hard-coded values

• Please add deprecation for hdds.tracing.enabled in
  

  ozone/hadoop-hdds/common/src/main/java/org/apache/hadoop/hdds/conf/OzoneConfiguration.java

  Line 314 in 5e009a3

  private static void addDeprecatedKeys() {

[adoroszlai]

Thanks @sravani-revuri for updating the patch. Please see HDDS-14961.patch for suggested changes.

[adoroszlai]

Thanks @sravani-revuri for the patch.