This project demonstrates an implementation of Event Sourcing and Saga Pattern in a Rails application, focusing on managing database consistency across multiple databases.

• Dynamic table creation across different database systems
• Event-driven architecture
• Saga pattern for distributed transaction management
• Asynchronous processing with robust error handling

• Ruby 3.3.1
• Rails 8.0.0
• PostgreSQL

1. Clone the repository

   git clone https://github.com/sasamuku/sample_event_sourcing.git
   cd sample_event_sourcing
   

2. Install dependencies

   bundle install
   

3. Start the docker compose

   docker compose up -d
   

4. Setup database

   bundle exec rails db:create
   bundle exec rails db:migrate
   

5. Start the server

   bundle exec rails server
   

• Event Sourcing: Tracks system state changes through event logs
• Saga Pattern: Manages distributed transactions with compensation mechanisms
• Async Jobs: Handle database synchronization tasks

• URL: https://github.com/RailsEventStore/rails_event_store
• Description:
  • Ruby/Rails library for event sourcing
  • Enables event storage, streaming, and replay
• Usage in this Project:
  • Logging events for database schema changes
  • Reconstructing system state at any point in time

• URL: https://github.com/rails/solid_queue
• Description:
  • Lightweight asynchronous job queueing system introduced in Rails 7.1
  • Database-based job queue enabling flexible asynchronous processing
• Usage in this Project:
  • Asynchronous execution of DDL operations
  • Job management in distributed transactions

• URL: https://github.com/jeremyevans/sequel
• Description:
  • High-performance and flexible Ruby database toolkit
  • Provides abstraction layer for multiple databases
• Usage in this Project:
  • Flexible connection to external databases
  • Dynamic database schema manipulation

Create a new table:

curl -X POST http://localhost:3000/table/create \
     -H "Content-Type: application/json" \
     -d '{"name": "my_new_table_123"}'

Delete a table:

curl -X POST http://localhost:3000/table/delete \
     -H "Content-Type: application/json" \
     -d '{"table_id": "2d7ea983-7844-4a1a-8b36-1dbc629d16e4"}'

Show table details:

curl -X POST http://localhost:3000/table/show \
     -H "Content-Type: application/json" \
     -d '{"table_id": "2d7ea983-7844-4a1a-8b36-1dbc629d16e4"}'

Add a column:

curl -X POST http://localhost:3000/table/column \
     -H "Content-Type: application/json" \
     -d '{"table_id": "2d7ea983-7844-4a1a-8b36-1dbc629d16e4", "column": {"name": "age", "type": "integer"}}'

Remove a column (by not specifying type):

curl -X POST http://localhost:3000/table/column \
     -H "Content-Type: application/json" \
     -d '{"table_id": "2d7ea983-7844-4a1a-8b36-1dbc629d16e4", "column": {"name": "age"}}'

The project implements a multi-database architecture with:

• Core DB for metadata
• BYODB for dynamic table creation
• Event-driven synchronization between databases

Run test suite:

bundle exec rspec

MIT License