Database Federation: Decentralized and ACL-Compliant Hive™ Databases

What this post added

This post details the migration strategy for decentralizing Uber's monolithic Hive data warehouse. It introduces the 'pointer manipulation' technique, where Hive Metastore entries are updated to point to new HDFS locations, enabling zero-downtime migrations without data duplication. The post outlines the four main components of the migration system: Bootstrap Migrator, Realtime Synchronizer, Batch Synchronizer, and Recovery Orchestrator. It elaborates on the Bootstrap Migrator's functionalities, including migration configuration, pipeline management, pre-migration checks, backup pointers, distributed data copying with checksum verification, target dataset location and partition recovery, and data quality checks. The core advantage highlighted is the cost savings and simplified data pipelines achieved by avoiding data duplication.