Production Investigation

Honeycomb Production Investigation

Structured workflows for debugging production issues. The MCP tools document their own parameters — this skill focuses on the sequence of tool calls and how to interpret results to reach a root cause.

The Core Analysis Loop

This workflow implements the core analysis loop (Define → Visualize → Investigate → Evaluate) from the observability-fundamentals skill. If BubbleUp returns nothing useful, the issue is often an instrumentation gap — add the missing attributes (see the otel-instrumentation skill) and try again.

Investigation Workflow

Step 1: Orient

1. get_workspace_context → environments and datasets
2. get_slos → any SLOs in violation? (frames severity)
3. get_triggers → any alerts firing? (narrows scope)
4. find_queries → has anyone investigated this before?

Step 2: Characterize the Problem

Run a broad query to see the shape of the issue:

• Latency spike: P99(duration_ms), HEATMAP(duration_ms) grouped by service or route
• Error surge: count failed operation spans (error=true) by service/route/category, then separately count exception event rows using event.name=exception and exception.type exists; use sampled trace.trace_id values to drill into representative traces
• Unknown: COUNT grouped by service.name to find which service has anomalous volume

Also call get_service_map — it shows P95 durations between services and can immediately reveal which dependency is slow.

Exception data has two query surfaces: operation failures belong on spans (error=true, span status, low-cardinality exception.slug/error category); full exception diagnostics may belong on trace-correlated Logs API event rows. Do not assume exception.* exists on the containing span. When investigating exceptions, discover the dataset schema first, query event.name=exception with exception.type exists and trace.trace_id exists, take a sample, then pass its trace.trace_id to get_trace(show_events=true). For legacy span-event exceptions, also check name=exception and meta.signal_type=trace; Logs API events use event.name/body and meta.signal_type=log.

If a service uses an exception-promoting LogRecordProcessor, some exception.* fields may also appear on the containing span. Treat that as an explicit client-side compatibility feature, not a Honeycomb guarantee: the event row remains authoritative for full diagnostics, and absence of parent-span fields does not mean the exception event is missing.

Step 3: BubbleUp to Find Differentiators

This is the highest-value step. Once you have a query showing the anomaly:

1. Run run_bubbleup on the query result, selecting the outlier region
2. BubbleUp compares outlier vs baseline distributions across all columns automatically
3. Look for fields where the distributions differ significantly

How to interpret BubbleUp results:

• Categorical fields (dimensions): A value overrepresented in outliers points to a cause (e.g., deployment.version=v2.3.1 is 90% of slow requests but only 20% of baseline)
• Numeric fields (measures): A shifted distribution shows correlated metrics (e.g., db.query_duration is much higher in outliers)
• Typical root causes surfaced: deployment version, region, user cohort, specific endpoint, feature flag

Step 4: Drill Into Traces

After BubbleUp identifies suspects:

1. Add BubbleUp findings as WHERE filters to narrow results
2. Pick a representative trace ID
3. Call get_trace to fetch the full trace

What to look for in the trace waterfall:

• Spans with disproportionate duration vs parent (the bottleneck)
• Sequential spans that could be parallelized (N+1 query patterns)
• Error spans — check span events for stack traces
• Gaps between child spans (missing instrumentation or idle wait)
• Service boundaries (where the trace crosses services)

Step 5: Verify Hypothesis

Form a hypothesis from BubbleUp + trace analysis, then confirm:

• Query WITH the suspected cause filtered in
• Query WITHOUT it (as a control)
• If the metrics diverge, you've found it

Step 6: Record Findings

Call create_board with:

• A text panel summarizing the root cause (Markdown)
• The key query run PKs that identified the problem
• Related SLOs if applicable

Investigation Patterns

Latency Spike

HEATMAP first → BubbleUp the slow region → trace a slow request → verify with filtered queries

Error Surge

Count failed operation spans by service/route/category → count Logs API exception events by event.name=exception and exception.type → sample trace.trace_id → get_trace(show_events=true) → verify with filtered queries. Do not use exception.message on the parent span as the only exception search.

Deployment Regression

P99 grouped by deployment.version → BubbleUp comparing new vs old → trace from new version → verify

Dependency Failure

get_service_map → P99 on the slow dependency → relational query (any.service.name) to measure user impact → trace an affected request

Stay on the Path

If you find yourself reasoning any of these, follow the workflow anyway:

• "The cause is obvious, I can skip BubbleUp" — BubbleUp routinely surfaces causes that seem obvious in hindsight but weren't the first guess. It also catches secondary causes you'd miss entirely.
• "I already know it's a deployment issue" — verify with Step 5. Confirmation bias is strongest during incidents. Query with and without the suspected cause.
• "Traces confirmed it, no need to verify" — a single trace is an anecdote. The verification query proves the pattern holds across all traffic, not just one request.
• "This is a simple issue, the full workflow is overkill" — the workflow takes minutes; a wrong diagnosis during an incident costs hours.

When Results Are Empty or Unclear

• No results: Check field names with find_columns, expand time range, verify environment/dataset
• BubbleUp shows no signal: Try a different time selection, add filters to isolate the anomaly more clearly, or select a different calculation
• Trace missing spans: Sampling, instrumentation gaps, or cross-environment trace split

Additional Resources

Reference Files

• ${CLAUDE_PLUGIN_ROOT}/skills/production-investigation/references/investigation-playbooks.md — Step-by-step playbooks for latency spikes, error surges, deployment regressions, dependency failures, SLO budget burn, and health checks
• ${CLAUDE_PLUGIN_ROOT}/skills/production-investigation/references/bubbleup-guide.md — Detailed BubbleUp usage: selection types, time specifications, pagination, result interpretation
• ${CLAUDE_PLUGIN_ROOT}/skills/production-investigation/references/trace-exploration.md — Trace structure, get_trace parameters and view modes, waterfall analysis, span events and links

Cross-References

• For the conceptual foundations of the core analysis loop, see the observability-fundamentals skill
• For query construction patterns, see the query-patterns skill
• For SLO/trigger context during investigations, see the slos-and-triggers skill