Zero_downtime_migrations

Overview

The LendingHome zero downtime migrations gem is a powerful tool designed for developers working with ActiveRecord 3+ and PostgreSQL databases. This gem aims to improve database migration processes by preventing locks and downtime during critical updates. It provides developers with clear guidelines and best practices to follow, ensuring that migrations are both effective and safe, particularly in high-traffic environments.

With this gem integrated into your project, you can focus on developing features rather than worrying about potential downtime caused by problematic migrations. Its proactive approach in catching issues at development and test stages significantly streamlines the overall deployment process while enhancing user experience during migrations.

Features

• Automatic Exception Handling: The gem raises exceptions during migrations when it detects potentially problematic operations to prevent locking issues.

• Best Practices Guidance: It offers detailed instructions on how to perform migrations "the zero downtime way," helping developers avoid common pitfalls.

• Batch Processing: Facilitates the backporting of default values for existing data in manageable batches, minimizing table locks during updates.

• Concurrent Indexing: Allows for the creation of indexes concurrently, preventing write-locks on tables and enabling ongoing data operations.

• Segregation of Migration Types: Encourages the separation of schema changes, data updates, and index additions into distinct migration files to enhance clarity and rollback safety.

• DDL Transaction Management: Provides guidance on when to disable DDL transactions to ensure that migrations can be reverted if issues arise during schema or data updates.

• Enhanced Development Workflow: By catching mistakes early, the gem improves the overall development experience, allowing for smoother deployment cycles with minimal downtime.