docs(observability): document the blank otel-collector auth failure mode - #90
Merged
Merged
Conversation
Found live 2026-07-30: docker/.env's LANGFUSE_OTEL_BASIC_AUTH had gone empty (cause unknown - predates this session's changes), so otel-collector sent Authorization: Basic <nothing> to langfuse-web, which rejected every batch with HTTP 401. This silently dropped ALL Claude Code telemetry for roughly 27 days (last real claude_code.tool observation before the fix: 2026-07-03) with zero visible error - devflow trace-review run just quietly reported 0 observations / 0 attribution, and nothing else surfaces this class of failure. Root-caused and fixed live (recomputed the value from ~/.config/zsh/secrets, docker compose up -d --force-recreate otel-collector - a plain restart does not re-read a changed .env), verified by a fresh claude_code.tool observation landing seconds later and devflow trace-review run immediately showing observations=24, attribution 1/29. Documented as gotcha #4 alongside the existing three, matching the file's own convention, so this is a 30-second diagnosis next time instead of the investigation it took here.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
TL;DR
Found live while re-verifying trace-review:
docker/.env'sLANGFUSE_OTEL_BASIC_AUTHhad gone empty, sootel-collectorsentAuthorization: Basic(nothing after it) tolangfuse-web, which rejected every batch with HTTP 401. This silently dropped all Claude Code telemetry for ~27 days with zero visible error —devflow trace-review runjust quietly reportedobservations: 0/ zero attribution.Root-caused and fixed live: recomputed the value from
~/.config/zsh/secrets,docker compose up -d --force-recreate otel-collector(env vars bake at container creation — a plainrestartdoesn't re-read a changed.env). Verified: a freshclaude_code.toolobservation landed seconds later, anddevflow trace-review runimmediately showedobservations=24,attribution 1/29.Change
Doc-only. Adds gotcha #4 to
eval/OBSERVABILITY.md's existing "Hard-won gotchas" list, matching its own convention (3 entries already there) — so this is a 30-second diagnosis next time.🤖 Generated with Claude Code