altinity-expert-clickhouse-logs

Analyze ClickHouse system log table health including TTL configuration, disk usage, freshness, and cleanup. Use for system log issues and TTL configuration.

Diagnostics

Run all queries from checks.sql in this skill's directory and analyze the results.

TTL Recommendations

| Log Table | Recommended TTL | Notes | |-----------|----------------|-------| | query_log | 7-30 days | Balance debugging vs disk | | query_thread_log | Disable or 3 days | Very verbose | | part_log | 14-30 days | Important for RCA | | trace_log | 3-7 days | Large, mostly for debugging | | text_log | 7-14 days | Important for debugging | | metric_log | 7-14 days | Useful for trending | | asynchronous_metric_log | 7-14 days | Low volume | | crash_log | 90+ days | Rare, keep longer |

KB articles

https://kb.altinity.com/altinity-kb-setup-and-maintenance/altinity-kb-system-tables-eat-my-disk/