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How to Handle Malformed Input

The file readers fail fast on malformed OTLP input. Use the error message to identify file discovery problems, payload shape mismatches, file size limits, unsupported metric shapes, or live-ingest admission failures.

SELECT * FROM read_otlp_traces('traces.jsonl');

Use this behavior when you convert telemetry exports. It surfaces bad data during the query instead of hiding it in downstream results.

Common Errors

Section titled “Common Errors”

No files matched the path or glob

SELECT * FROM read_otlp_logs('missing/*.jsonl');
-- No files found that match the pattern

Check the DuckDB working directory or use an absolute path.

Malformed OTLP input

SELECT * FROM read_otlp_traces('malformed.jsonl');
-- OTLP parse error on malformed.jsonl: ...

Check that the payload shape matches the reader:

  • read_otlp_traces expects resourceSpans.
  • read_otlp_logs expects resourceLogs.
  • read_otlp_metrics_* expects resourceMetrics.

Unsupported metric shape

The extension raises an unsupported-function error for read_otlp_metrics() and read_otlp_metrics_summary(). Use a typed metric reader:

SELECT * FROM read_otlp_metrics_gauge('metrics.jsonl');
SELECT * FROM read_otlp_metrics_sum('metrics.jsonl');
SELECT * FROM read_otlp_metrics_histogram('metrics.jsonl');
SELECT * FROM read_otlp_metrics_exp_histogram('metrics.jsonl');

File is too large

The readers limit each file to 100 MB to avoid memory exhaustion. Split large exports with the OpenTelemetry Collector file exporter rotation settings, or query smaller files through globs.

Live Ingest Errors

Section titled “Live Ingest Errors”

For otlp_serve, the server returns HTTP errors as JSON. Common cases:

  • 401 for missing or invalid tokens.
  • 413 for bodies larger than max_body_bytes.
  • 415 for unsupported content types or encodings.
  • 503 when max_buffered_bytes backpressure rejects a request.

See the Live Ingest Reference for the complete contract.

Section titled “Related”