SQL Adapter for Background Tasks

[UtkarshDixit-97]

This is a Sample PR of a very basic implementation of SQL based WAL storage for deffered task.

• Architecture overview - Implemented a lightweight, cloud-native SQL adapter for Rage::Deferred to replace the disk-based WAL. The adapter persists deferred tasks durably in a SQL database while keeping task execution local to the same process.

• Key components -

  • Rage::Deferred::Backends::SQL – The main adapter implementing add, remove, and pending_tasks
  • Rage::Deferred::Queue – Uses the backend for persistence and replay
  • Automatic table creation (rage_deferred_tasks) with task_id (UUID), serialized_task, publish_at, and status
  • Configuration integration via Rage.configure { config.deferred.backend = :sql }

• Implementation strategy -

  • Database access during framework boot so we can create rage_deferred_tasks table(later on checking pending_tasks[], which will return pending or failed tasks )
  • For any task which is referred we will store log in db table before enqueing it in memory
  • On task is scheduled and completed (remove), the row is deleted instead of marked for deletion

• Technologies or libraries involved

  • ActiveRecord (for connection management and schema operations)
  • SQLite3 (currently tested) / PostgreSQL/MySQL (future implementation if proposal is accepted in GSOC)
  • Rage’s Fiber Scheduler + custom ConnectionPool extension
  • SecureRandom.uuid for task IDs

For the Application to switch to sql based log, create a file --> config/initializers/rage.rb

Rage.configure do
  # Other configurations if any...

  config.deferred.backend = :sql
  # Optional: custom table name
  # config.deferred.backend = :sql, table_name: "rage_deferred_tasks"
end