Metrics Reference

Metrics are always collected and merged into RunResult.metrics_*.

Counters

• rows_written_total
• writer_flushes
• errors_total
• dlq_spooled_files_total
• dlq_rescued_total
• dlq_remaining_total
• dlq_spool_failed_total
• schema_missing_cols_filled — cells filled as null for missing schema columns in non‑strict mode
• schema_extra_cols_preserved_count — number of extra input columns preserved beyond schema
• inmem_dedup_dropped_rows — rows removed by in‑memory unique_key dedup/upsert (keep="last")

Histograms

• Global:
• fetch_duration_s
• parse_duration_s
• http_duration_s
• writer_flush_duration_s
• Per table:
• writer_flush_duration_s.{table}
• writer_rows.{table}

Snapshots

• req_q_len_after_producer
• req_q_len_after_req_join
• pkt_q_len_after_producer
• pkt_q_len_after_pkt_join

Summaries

• Global p95/p99 durations
• Per‑table p50/p95/p99 for writer_flush_duration_s.{table}, writer_rows.{table}