[jira] [Created] (CAMEL-23993) Flaky SpanPropagationUpstreamTest - SpanComparator missing tie-breaking on equal timestamps

["Guillaume Nodet (Jira)" <ji...@apache.org>]

Guillaume Nodet created CAMEL-23993:
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             Summary: Flaky SpanPropagationUpstreamTest - SpanComparator missing tie-breaking on equal timestamps
                 Key: CAMEL-23993
                 URL: https://issues.apache.org/jira/browse/CAMEL-23993
             Project: Camel
          Issue Type: Bug
          Components: camel-telemetry
            Reporter: Guillaume Nodet


SpanPropagationUpstreamTest is flaky across all telemetry modules (camel-telemetry, camel-telemetry-dev, camel-micrometer-observability, camel-opentelemetry2).

Develocity shows a ~20% failure rate (35/175 runs).

*Root cause:* SpanComparator sorts spans by start timestamp only. When spans have identical start timestamps (common on fast systems where execution happens within the same nanosecond), the sort is non-deterministic. Java's TimSort preserves insertion order for equal elements, and InMemorySpanExporter adds spans in end-order (innermost/leaf spans end first). This reverses the expected creation-order, causing positional assertions like {{spans.get(0)}} to retrieve the wrong span.

*Fix:* Add {{endEpochNanos}} (descending) as a secondary sort key in SpanComparator. Parent spans always end after their children, so when start times tie, sorting by end time descending puts parent spans first — matching the hierarchy order the tests expect.

The fix applies to all 4 SpanComparator implementations:
- {{components/camel-micrometer-observability/.../CamelOpenTelemetryExtension.java}}
- {{components/camel-opentelemetry2/.../CamelOpenTelemetryExtension.java}}
- {{components/camel-telemetry/.../mock/MockTrace.java}}
- {{components/camel-telemetry-dev/.../DevTrace.java}}

Additionally, the mock-based comparators (camel-telemetry, camel-telemetry-dev) used {{(int)(longA - longB)}} which has an integer overflow bug. The fix uses {{Long.compare()}} instead.



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