Query Error Rate Spike

critical

reliabilityUpdated Feb 6, 2026

Elevated failed query rate indicates systemic issues like resource exhaustion, configuration errors, or application bugs affecting database stability.

Sources

Useful queries for troubleshooting | ClickHouse Docsclickhouse.com

Essential Monitoring Queries - part 2 - SELECT Queries - ClickHouseclickhouse.com

How to Monitor ClickHouse Query Performance with OpenTelemetryoneuptime.com

Technologies:

ClickHouseSymptoms of this issue are visible in ClickHouse metrics and logs

clickhouse.query.exceptions

How to detect:

Track FailedQuery count from ClickHouseProfileEvents and query exceptions in system.query_log. Alert when error rate exceeds 5% of total queries or shows sudden spikes.

Recommended action:

Review system.errors for recent error types and messages, analyze failed queries in system.query_log for common patterns, check system resource utilization (CPU, memory, disk), and investigate client connection issues or timeout configurations.