Distributed File System

Design a distributed file system with strong consistency for file listings.

Requirements:

• mkdir(path) - Create directory
• ls(path) - List contents (strongly consistent)
• put(path, file) - Upload file
• get(path) - Download file
• delete(path) - Delete file/directory

Key Constraint: Strong consistency for listings (unlike S3's eventual consistency)

Discussion Points:

• Metadata storage (use directory as partition key)
• File chunking for large files
• Write-ahead logging for durability
• Recursive directory deletion handling
• Namenode HA (active/standby)
• Local Secondary Index for strong consistency

Common Pitfall: Don't design the storage layer from scratch - assume blob storage exists. Focus on metadata management and consistency.