All About Zookeeper (And ClickHouse Keeper, too!)

All About Zookeeper (And ClickHouse Keeper, too!)

ClickHouse clusters depend on ZooKeeper to handle replication and distributed DDL commands. In this webinar, we’ll explain why ZooKeeper is necessary, how it works, and introduce the new built-in replacement.

CVE-2021-44228 Log4J Vulnerability and ClickHouse

CVE-2021-44228 Log4J Vulnerability and ClickHouse

ClickHouse and Altinity products are not subject to CVE-2021-44228 based on knowledge available today. If you run any Java applications, you should check whether they have the affected Log4J library version. Check here for advice to detect and remediate the problem. 

SigNoz and ClickHouse Zookeeper Replacement — August SF Bay Area Meetup

SigNoz and ClickHouse Zookeeper Replacement — August SF Bay Area Meetup

The August 2021 ClickHouse SF Bay Area meetup featured two excellent talks on our favorite database. SigNoz and Yandex explored observability and Zookeeper replacement followed by many questions. Eliminating Zookeeper is a long-awaited improvement, and the talk is the first time it has been publicly presented. Check out event replays and details here.

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.