Estimation

• Target

  • Throughput

  • Bandwidth

  • Storage

Target

• 1 billion registered user. Each free user has 1TB storage space.

• Daily active user represents 20% of the entire user, namely 0.2 billion.

• Each DAU uploads and downloads 4 file per day.

Throughput

• Average and peak QPS.

# Average QPS
0.2 * 10^9 * 4 files / (24 * 60 * 60) = 10^4

# Peak QPS
2 * 10^4

Bandwidth

• Suppose that each file uploaded/downloaded is 1MB.

# Average bandwidth
10^4 * 1MB = 10 GB/s = 80Gb/s

# Peak bandwidth
160 Gb/s

Storage

• Lots of files are duplicated (Videos, books, software installation packages). And most users won't use the entire space. Instead they typically only use 10% of the entire space.

• The total space needed is

1 * 10^9 * 1TB * 10% = 10^8 TB