In this article, we'll explore the intricacies of designing a robust and user-friendly online file-sharing system that meets the demands of today's users and businesses.

Understanding the Landscape

Before diving into the design process, it's crucial to understand the landscape of online file sharing. From individual users sharing personal files to enterprises collaborating on sensitive documents, the requirements for file-sharing systems vary widely. Key considerations include:

• User Needs: Understanding the needs of different user groups, such as individuals, businesses, and organizations, is essential for designing a system that caters to diverse use cases.
• Security Requirements: Ensuring the confidentiality, integrity, and availability of shared files is paramount, especially for sensitive or confidential information.
• Scalability and Performance: As user traffic and data volumes grow, the system must be able to scale seamlessly to accommodate increasing demand while maintaining optimal performance.
• Collaboration Features: Supporting collaboration features such as real-time editing, version control, and commenting enhances productivity and fosters teamwork.

Functional Requirements:

• User should be able to download/upload, update, delete files from any device
• Files should be synchronised in all the devices that the user is logged in
• History/versioning of files (snapshotting of data)

Non-functional requirements

• Our service needs to be highly available

• The system should be highly reliable; any uploaded file should never be lost

• System should support large files uploading

High Level Design

How to have a better Block Server?

To set up a block upload server using cloud storage services:

• Choose a cloud storage provider like Amazon S3, Google Cloud Storage, or Azure Blob Storage.
• Use serverless platforms or containerized solutions for server-side logic.
• Implement API endpoints for handling uploads, authentication, and storage operations.
• Develop client-side logic for chunking large files and uploading them.
• Ensure support for resumable uploads to handle interruptions.
• Monitor server performance and storage usage for scaling as needed.

What is the best way to have a Metadata Server?

To create a metadata server:

• Choose a distributed key-value store or NoSQL database.
• Design a schema for metadata storage.
• Implement CRUD operations for metadata.
• Ensure data consistency and integrity.
• Scale horizontally to handle increasing loads.
• Implement security measures.
• Monitor performance and maintain the server.
• Backup data for disaster recovery.

Synchronisation Service

For every new update, synchronisation service is responsible to efficiently process updates and apply changes to other subscribed devices to keep their local db and remote db in sync.

Synchronisation service should be designed to transmit as less data as possible to avoid unnecessary network bandwidth and achieve a better response time. Server and client can calculate a hash (SHA-256) to check if chunk is updated or not. On server also, if we have the chunk with similar hash(even from another user), we can use the same chunk instead of creating a new copy to avoid data deduplication.

Conclusion

Designing a seamless online file-sharing system requires careful consideration of user needs, security requirements, scalability, and performance. By leveraging modern technologies, best practices, and a user-centric approach, organizations can develop file-sharing solutions that enhance productivity, foster collaboration, and meet the evolving needs of users and businesses in today's digital landscape.