High exporter timeout rate indicates pipeline degradation

Exporter timeout failure rate exceeds 5% for 5+ minutes. Calculated as send_failed / (sent + send_failed). Indicates systematic issue with exports causing data loss or delays.

Alert triggers when rate(otelcol_exporter_send_failed_spans[5m]) / (rate(otelcol_exporter_sent_spans[5m]) + rate(otelcol_exporter_send_failed_spans[5m])) > 0.05 for 5 minutes. Investigate root cause: check backend processing time, network latency, DNS resolution, resource constraints. Apply appropriate fix from diagnostic guide based on root cause identified.