Health overview and routing

Answers "is this server healthy, and which area needs a deeper look?" from system.metrics, system.asynchronous_metrics, system.parts, system.disks, system.tables, system.query_log, system.errors and system.text_log. It is single-host by design; per-replica divergence belongs to the specialist skills. Run altinity-expert-clickhouse-connection first if the connection mode, cluster and time window are not yet established.

Query packs

• checks.sql — 14 checks: object counts, memory vs RAM, primary-key and dictionary RAM, disk usage, replication summary, system log TTL and size, hourly query error rate, part_log errors, system.errors top codes, detached parts, recent warnings in text_log, background pool utilization.
• metrics.sql — 13 alert checks (ids A3.0.x) that return rows only when a threshold is breached; an empty result is OK. Checks A3.0.4 and A3.0.5 have two version-specific alternatives (@requires version<26.8 / version>=26.8): run the one matching the server version.
• ddl_queue.sql — 1 check on the ON CLUSTER DDL queue; @requires keeper.

How to run the query packs

1. Read each pack file from this skill's directory (the skill loader prints the directory path).
2. Run statements one at a time, never a whole file. Statements end with ; and start with a -- @check <id> <title> header; keep the id with its result.
3. Honor -- @requires: skip the statement when the named table is missing, when keeper is required and the server has no Keeper/ZooKeeper, or when the version condition is not met. List skipped ids with the reason.
4. Keep {cluster} as written when a cluster macro exists; otherwise apply the connection skill's rewrite rule. Any other {placeholder} is a template variable: substitute a real value first or skip the statement.
5. On an error, record the check id and the first line of the error, then continue. Only for UNKNOWN_IDENTIFIER, run DESCRIBE TABLE system.<table> and drop the missing column.
6. A severity column is the verdict for that row. Copy it; do not re-grade.