Introduction to HBCK2

HBCK2 is an essential tool for HBase administrators, providing functionalities to diagnose and repair various inconsistencies that can occur in an HBase cluster.

These inconsistencies often involve discrepancies between the hbase:meta table (which stores region assignments and locations) and the actual state of region directories on HDFS. Understanding and correctly using HBCK2 commands is crucial for maintaining a healthy and operational HBase environment.

Before You Start

• Always back up your data before performing any repair operations, especially those involving the --fix option.
• Understand the risks: Commands marked with "extreme caution" or "dangerous" can lead to data loss or further inconsistencies if misused. Proceed with care and ensure you understand the implications of each command.
• Consult HBase documentation: For complex scenarios or before major repairs, always refer to the official Apache HBase documentation for the most up-to-date best practices and warnings.