Snapshot profiling: SPLUNK_SNAPSHOT_SELECTION_PROBABILITY has no maximum enforcement

[pmcollins]

Summary

The SPLUNK_SNAPSHOT_SELECTION_PROBABILITY env var accepts any float value with no upper bound validation, but the GDI spec sets a maximum selection rate of 0.10.

Spec requirement

GDI Specification v1.8.0 — behaviors.md (Trace Selection):

Trace selection MUST be randomized with the following constraints:

• Default selection rate of 0.01
• Maximum selection rate of 0.10

Note: there is an internal inconsistency in the spec — configuration.md says MUST be 0 < n <= 1, while behaviors.md says max 0.10. The behaviors section is more specific.

Current state

src/splunk_otel/propagator.py:75-77 and src/splunk_otel/distro.py:134 pass the value directly to TraceIdRatioBased with no clamping or warning. A user setting SPLUNK_SNAPSHOT_SELECTION_PROBABILITY=1.0 would get 100% selection with no error.

Expected

• Clamp the value to (0.0, 0.10] or log a warning when the value exceeds 0.10
• Raise or warn on values <= 0

References

• src/splunk_otel/propagator.py:75-77
• src/splunk_otel/distro.py:134