File Storage Service

Scalable S3-compatible storage for user uploads, assignments, and course materials

Requirements Document

Comprehensive requirements for the File Storage Service in the KnowledgeTracker Platform.

1. Functional Requirements

1.1 File Upload & Management

  • Multipart file upload for large files (up to 5GB)
  • Drag-and-drop file upload interface
  • File type validation and size limits
  • Folder/directory structure for organization
  • File versioning and revision history
  • Rename, move, copy, and delete file operations

1.2 Access Control & Permissions

  • Private, public, and shared file visibility settings
  • Role-based access control (owner, editor, viewer)
  • Shareable links with expiration dates
  • Password-protected file sharing
  • Organization-wide storage quotas and limits

1.3 File Processing & Preview

  • Thumbnail generation for images and videos
  • In-browser preview for documents (PDF, Office files)
  • Video transcoding for web-friendly formats
  • Image optimization and compression
  • Document text extraction for search indexing

1.4 Download & Delivery

  • Direct download and streaming capabilities
  • Bulk download as ZIP archive
  • Resume-able downloads for large files
  • CDN delivery for fast global access
  • Bandwidth throttling and rate limiting

1.5 Storage Analytics

  • Storage usage by user and organization
  • File type distribution and popular content
  • Download statistics and access logs
  • Unused or orphaned file detection

1.6 Multi-Tenant Storage

  • Isolated storage buckets per organization
  • Organization-specific storage quotas and policies
  • Custom retention and deletion policies

2. Non-Functional Requirements

2.1 Performance

  • Upload speed up to 100MB/s for large files
  • File listing and metadata retrieval < 500ms
  • CDN cache hit rate > 90% for popular files

2.2 Scalability

  • Support for petabytes of total storage
  • Horizontal scaling with object storage (S3, MinIO)
  • Auto-scaling for traffic spikes

2.3 Reliability

  • 99.99% file availability and durability
  • Geographic replication for disaster recovery
  • Automated backup and versioning
  • Checksum verification for data integrity

2.4 Security

  • Encryption at rest (AES-256) and in transit (TLS)
  • Virus and malware scanning on upload
  • DLP (Data Loss Prevention) for sensitive content
  • Secure signed URLs with expiration

2.5 Compliance

  • GDPR compliance for data storage and deletion
  • COPPA compliance for educational content
  • Data residency options (EU, US, Asia)

3. Integration Requirements

3.1 Internal Microservices

  • Content Delivery: Course material storage
  • Assessment Engine: Assignment submission files
  • User Management: Profile pictures and documents
  • Certificate Generation: Certificate PDF storage

3.2 External Services

  • Object Storage: AWS S3, Google Cloud Storage, MinIO
  • CDN: CloudFlare, AWS CloudFront, Fastly
  • Virus Scanning: ClamAV, VirusTotal API

Requirements Validation

Use this requirements document alongside the Database Design to validate:

  • File metadata storage (name, size, type, owner)
  • Permission and access control schema
  • Version history and audit trail tables
  • Storage quota tracking per organization