A New Way to Restore ClickHouse After ZooKeeper Metadata Is Lost

A New Way to Restore ClickHouse After ZooKeeper Metadata Is Lost

Every ClickHouse user has experienced data loss due to user error or operational failure with Zookeeper at least once in their lifetime. If a failure resulted in metadata loss, ClickHouse tables can turn into pumpkins–you can query but you cannot insert more data. But as of ClickHouse version 21.7, this has changed with a new SQL Command. Keep reading to learn more.

Introduction to ClickHouse Backups and clickhouse-backup

Introduction to ClickHouse Backups and clickhouse-backup

Data backups are an inglorious but vital part of IT operations. They are most challenging in “big data” deployments, such as analytics databases. This article will explore the plumbing involved in backing up ClickHouse and introduce the clickhouse-backup tool for automating the process.