ADR-0009: Implementation of Real-Time Collaboration Features
Status
Accepted
Context
Real-time collaboration on musical scores is a highly requested feature that is currently not well-supported by existing music notation software. Musicians, composers, and educators need the ability to work simultaneously on the same piece, seeing each other's changes in real-time, similar to collaborative document editing platforms. FrankenScore's architecture provides a unique opportunity to implement this feature effectively.
Decision
We will implement real-time collaboration as a core feature of FrankenScore, leveraging our existing architecture and technologies to provide a seamless, efficient, and reliable collaborative editing experience.
Rationale
1. Existing Architecture Advantages:
- Separation of frontend and backend allows for a cloud-hosted backend that can manage concurrent edits.
- The Piece Manager can handle multiple concurrent connections to the same piece.
2. Transactional Model:
- FrankenScore's existing transactional system with automatic retries is well-suited for handling concurrent edits and resolving conflicts.
3. Efficient Communication:
- gRPC's binary protocol ensures low-latency communication between clients and the server, crucial for real-time collaboration.
- Nippy's efficient serialization can be used for larger data transfers when saving and loading music files.
4. Immutable Data Structures:
- Clojure's immutable data structures simplify the implementation of conflict resolution and change merging.
5. Market Differentiation:
- Implementing this highly requested feature will significantly differentiate FrankenScore from competitors.
6. Extensibility:
- The collaboration system can be designed to work with FrankenScore's plugin architecture, allowing for custom collaborative features.
Consequences
Positive:
Negative:
Implementation Approach
1. Extend Piece Manager:
- Implement session management for collaborators.
2. Real-Time Synchronization:
- Use gRPC streaming for real-time updates between clients and server.
- Implement a publish-subscribe system for broadcasting changes to all connected clients.
3. Conflict Resolution:
- Extend the transactional system to handle and resolve conflicts between concurrent edits.
- Implement Operational Transformation or a similar algorithm to ensure consistency across clients.
4. Change Representation:
- Use VPDs to efficiently communicate changes between clients and server.
- Implement a change compression mechanism for bandwidth optimization.
5. Collaborative UI:
- Develop UI components to show collaborator presence and activities.
- Implement visual indicators for remote cursor positions and selections.
6. Access Control:
- Develop a permission system for different levels of access (view, edit, admin).
- Implement secure invitation and joining mechanisms for collaborative sessions.
7. Offline Support:
- Implement a change queuing system for offline edits.
- Develop a robust synchronization mechanism for when clients come back online.
8. Version History:
- Leverage the undo/redo system to provide a browsable history of changes.
- Implement features to revert to or branch from previous states of the score.
9. Large Data Handling:
- Implement intelligent chunking for transferring large scores or changes.
10. Plugin API:
- Extend the plugin API to allow integration with the collaboration system.
- Provide hooks for plugins to participate in conflict resolution and change representation.
11. Testing and Validation:
- Develop a comprehensive test suite simulating various collaborative scenarios.
- Implement stress testing for concurrent edits on large scores.
Alternatives Considered
1. Peer-to-Peer Collaboration:
- Rejected due to complexities in NAT traversal and maintaining consistency across all peers.
2. WebSocket-based Solution:
- Considered but rejected in favor of gRPC for its better performance and type safety.
3. Third-party Collaboration Platforms:
- Explored but deemed insufficient for the specialized needs of music notation collaboration.
Notes
Accepted
Context
Real-time collaboration on musical scores is a highly requested feature that is currently not well-supported by existing music notation software. Musicians, composers, and educators need the ability to work simultaneously on the same piece, seeing each other's changes in real-time, similar to collaborative document editing platforms. FrankenScore's architecture provides a unique opportunity to implement this feature effectively.
Decision
We will implement real-time collaboration as a core feature of FrankenScore, leveraging our existing architecture and technologies to provide a seamless, efficient, and reliable collaborative editing experience.
Rationale
1. Existing Architecture Advantages:
- Separation of frontend and backend allows for a cloud-hosted backend that can manage concurrent edits.
- The Piece Manager can handle multiple concurrent connections to the same piece.
2. Transactional Model:
- FrankenScore's existing transactional system with automatic retries is well-suited for handling concurrent edits and resolving conflicts.
3. Efficient Communication:
- gRPC's binary protocol ensures low-latency communication between clients and the server, crucial for real-time collaboration.
- Nippy's efficient serialization can be used for larger data transfers when saving and loading music files.
4. Immutable Data Structures:
- Clojure's immutable data structures simplify the implementation of conflict resolution and change merging.
5. Market Differentiation:
- Implementing this highly requested feature will significantly differentiate FrankenScore from competitors.
6. Extensibility:
- The collaboration system can be designed to work with FrankenScore's plugin architecture, allowing for custom collaborative features.
Consequences
Positive:
- Unique feature offering in the music notation software market.
- Enhanced user experience for collaborative composition and education.
- Leverages and validates FrankenScore's core architectural decisions.
- Potential for new use cases and market opportunities (e.g., remote music education, distributed orchestras).
Negative:
- Increased complexity in backend logic to manage concurrent edits.
- Potential for increased server infrastructure costs.
- Need for additional security measures to manage access control and data privacy.
Implementation Approach
1. Extend Piece Manager:
- Implement session management for collaborators.
2. Real-Time Synchronization:
- Use gRPC streaming for real-time updates between clients and server.
- Implement a publish-subscribe system for broadcasting changes to all connected clients.
3. Conflict Resolution:
- Extend the transactional system to handle and resolve conflicts between concurrent edits.
- Implement Operational Transformation or a similar algorithm to ensure consistency across clients.
4. Change Representation:
- Use VPDs to efficiently communicate changes between clients and server.
- Implement a change compression mechanism for bandwidth optimization.
5. Collaborative UI:
- Develop UI components to show collaborator presence and activities.
- Implement visual indicators for remote cursor positions and selections.
6. Access Control:
- Develop a permission system for different levels of access (view, edit, admin).
- Implement secure invitation and joining mechanisms for collaborative sessions.
7. Offline Support:
- Implement a change queuing system for offline edits.
- Develop a robust synchronization mechanism for when clients come back online.
8. Version History:
- Leverage the undo/redo system to provide a browsable history of changes.
- Implement features to revert to or branch from previous states of the score.
9. Large Data Handling:
- Implement intelligent chunking for transferring large scores or changes.
10. Plugin API:
- Extend the plugin API to allow integration with the collaboration system.
- Provide hooks for plugins to participate in conflict resolution and change representation.
11. Testing and Validation:
- Develop a comprehensive test suite simulating various collaborative scenarios.
- Implement stress testing for concurrent edits on large scores.
Alternatives Considered
1. Peer-to-Peer Collaboration:
- Rejected due to complexities in NAT traversal and maintaining consistency across all peers.
2. WebSocket-based Solution:
- Considered but rejected in favor of gRPC for its better performance and type safety.
3. Third-party Collaboration Platforms:
- Explored but deemed insufficient for the specialized needs of music notation collaboration.
Notes
- Regularly benchmark the collaboration system's performance, especially with large scores and many concurrent users.
- Implement analytics to understand collaboration patterns and optimize accordingly.
- Consider implementing "roles" within collaborative sessions (e.g., conductor, section leader).
- Explore integration with version control systems for advanced collaboration workflows.
- Develop clear documentation and tutorials for effective collaborative use of FrankenScore.
- Investigate potential for using the collaboration system for live performance applications.
- Consider implementing a "replay" feature to review the collaborative creation process.
- Explore options for audio/video chat integration to enhance remote collaboration.
- Regularly gather user feedback on the collaboration experience and iterate on the implementation.
- Stay informed about advancements in distributed systems and real-time collaboration technologies.