Data logs: The latest evolution in Meta’s access tools

What this post added

Introduced data logs as a new capability within the Download Your Information (DYI) tool, enabling users to access granular data previously only available in the data warehouse (Hive). This involved developing a system to batch user requests, perform optimized INNER JOINs between user ID tables and data partitions in Hive, and post-process raw data into user-friendly HTML files. Key technical challenges addressed include the inefficiency of individual queries on massive Hive tables, the computational and storage costs of caching, and ensuring data correctness through verification steps to mitigate Spark concurrency bugs.