Altinity Expert Clickhouse Part Log

Diagnose ClickHouse issues by analyzing system.part_log (part creation, merges, mutations, downloads, removals, moves). Use for too many parts / micro-batch inserts, merge backlog or slow merges, mutation storms (ALTER DELETE/UPDATE), unusual replication DownloadPart churn, unexpected RemovePart spikes, or ZooKeeper/Keeper znode growth correlated with part activity.

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Part Log Based Diagnostics

Run all queries from checks.sql in this skill's directory (cluster-wide) and interpret the top offenders by rate (events/min), volume (rows/bytes), and errors.

Notes:

  • Default timeframes are relative (e.g., last 1h/6h/24h). Only switch to an explicit time range when the user provides one in the prompt.
  • Replace {cluster} with your ClickHouse cluster name (DataGrip).
  • Keep queries time-bounded (event_time > now() - INTERVAL ...) and use LIMIT.
  • If a query fails due to schema differences, run DESCRIBE TABLE system.part_log and drop only missing fields.

Cross-module triggers:

  • High NewPart rate / micro-batches → load altinity-expert-clickhouse-ingestion + altinity-expert-clickhouse-merges
  • High MutatePart rate → load altinity-expert-clickhouse-mutations
  • Many DownloadPart → load altinity-expert-clickhouse-replication
  • Merge saturation / slow merges → load altinity-expert-clickhouse-merges + altinity-expert-clickhouse-storage

altinity/altinity-skills/tree/main/altinity-expert-clickhouse/skills/altinity-expert-clickhouse-part-log commit 03af628a3d

Frequently asked questions

npx skillmds@latest add altinity/altinity-expert-clickhouse-part-log