OBSERVABILITY · TRACE WATERFALL INSPECTOR
Trace observability: distinguish execution from export
Inspect actual span IDs, parent relationships, sampling decisions and a deterministic execution schedule.
Your experiment
Turn off span capture. The modeled work still happens, but no spans are exported. Explain why missing telemetry does not mean the request performed no work.
Click any waterfall row or use the span selector. A gold outline marks your selection; details include the exact parent ID, timestamps, status and export decision.
The one-minute inspection is a slowed visualization of the modeled millisecond timeline, not a measured request. Inclusive parent and child durations overlap.
Selected span
Offline schedule and trace-context exercise; no agent, network request or OpenTelemetry exporter runs. Header validation deliberately supports version 00 only and is not a complete forward-compatible W3C parser. IDs are deterministic teaching fixtures, not production ID generation. Later tool durations increase by 25% of the first tool duration; database work occupies 20–80% of each tool span. A dependency failure marks its ancestors as failed in this application model. Sampling is a local policy, not an authorization boundary. Newly rooted remote traces default to sampled when context is not forwarded. The canvas shows modeled work even when telemetry is not exported, exposing the blind spot. No clock skew, spans lost in transport, baggage, tracestate or real latency is modeled. W3C Trace Context · OpenTelemetry trace concepts.
Distinguish running work from available evidence
A service can execute work even when its telemetry is not recorded. This fixture keeps that work visible intentionally, so the recording controls do not deceptively erase the cause of a blind spot. The gray bars indicate unexported modeled spans. Compare the full schedule, selected record and exported count to distinguish application execution from a local sampling or capture decision.
Configure the schedule and context
Incoming traceparent accepts version-zero lowercase hexadecimal fields with nonzero trace and parent IDs. Invalid input starts a new synthetic root and displays a validation message. Forward context to remote tools chooses whether tools retain the incoming trace or start separate roots. Run tools in parallel changes their schedule. Remote tools selects one through four branches. Local work before and after tools supplies both local intervals. First tool duration is the base duration; each later tool adds twenty-five percent of that base per index. Dependency fault marks either the first database or every database as failed and propagates the error through modeled ancestors.
Reproduce an unsampled trace and disconnected remote roots
Use the default valid header but change its last field from 01 to 00. With context forwarding, capture enabled and Honor incoming unsampled flag enabled, all eight spans execute but none are exported. Disable the honor flag and all eight are exported under this teaching policy. Restore honoring and disable context forwarding: root and agent remain unrecorded, while six remote tool/database spans use new sampled roots. The result has four trace IDs and six exported spans. No extra latency is created by the missing correlation; the parallel request still lasts 390 milliseconds.
Inspect recording independently of execution
Capture and export spans switches recording on or off without removing the modeled execution. Honor incoming unsampled flag applies when a valid incoming header is unsampled; respecting that decision suppresses the propagated trace. New remote roots default to sampled if context forwarding is disabled. Inspect a span selects its exact JSON record, and clicking a waterfall row makes the same selection. Play and Pause reveal the schedule across sixty inspection seconds. Next span boundary jumps to a start or end; Restart rewinds; Speed changes viewing pace; Inspection time scrubs. Parameter changes restart playback unless reduced motion is requested. The full-scenario preview and selected JSON are not limited to already completed spans; the filled bars show inspected progress.
Know what the fixture does not observe
Database work occupies twenty through eighty percent of its enclosing tool duration. IDs are deterministic teaching identifiers, not production generators. The parser intentionally covers version zero rather than all forward-compatible trace-context cases. No actual OpenTelemetry collector, exporter acknowledgement, baggage, tracestate, network span loss, clock skew or ADK agent is present. An exported-span count is a configured local recording decision, not proof that a backend accepted the record. Overlapping inclusive spans must not be added to claim request latency. The synthetic schedule supports reasoning about causality, visibility and aggregation; it does not measure an installed service.