Pending mutations

Find stuck ALTER/DELETE mutations with failure reason; blocks schema changes

clickhouse-client -q "SELECT database, table, mutation_id, latest_fail_reason FROM system.mutations WHERE is_done=0"
tool
clickhouse17 commands
tags
clickhousetroubleshootingdebugmonitoring

More clickhouse commands

  • Connect to clickhouse-client
    clickhouse-client -h clickhouse -u default --password <pass> --database mydb

    Open interactive ClickHouse CLI session

  • Show databases
    clickhouse-client -q 'SHOW DATABASES'

    List all databases in ClickHouse

  • Show tables
    clickhouse-client -q 'SHOW TABLES FROM mydb'

    List all tables in a database

  • Table size
    clickhouse-client -q "SELECT table, formatReadableSize(sum(bytes)) AS size FROM system.parts WHERE active AND database='mydb' GROUP BY table ORDER BY sum(bytes) DESC"

    Show disk usage per table in a database

  • Running queries
    clickhouse-client -q 'SELECT query_id, user, elapsed, query FROM system.processes ORDER BY elapsed DESC'

    List all currently running queries with elapsed time

all 17 clickhouse commands