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Bluesky (AT Protocol) vs URL Shortener

Bluesky (AT Protocol)

Bluesky (AT Protocol)

Federated social network. Your data lives in your own Personal Data Server, and feeds and search are pluggable services that consume the global firehose.

Components (7)

  • Bluesky Client
  • Your PDS
  • Relay (Firehose)
  • AppView
  • Custom Feed Generator
  • DID Resolver
  • Timeline Index

Headline numbers

  • Posts / sec (avg)~870/sec
  • Firehose throughput~5K events/sec
  • AppView timeline index size~50 GB
URL Shortener

URL Shortener

Hashing, key generation, read-heavy caching.

Components (6)

  • Client
  • API Gateway
  • Write Service
  • Read Service
  • Redis
  • Postgres

Headline numbers

  • Write QPS (avg)~1,200/sec
  • Read QPS (avg)~120,000/sec
  • Storage per year~5 TB

Key differences

Only in Bluesky (AT Protocol)
  • Relay (Firehose)
In both
  • Client
  • Service
  • Database
Only in URL Shortener
  • API Gateway
  • Redis

Flow shape

Bluesky (AT Protocol) flows
  • Post a skeet4 steps
  • Open the home timeline4 steps
  • Main Relay goes offline4 steps
URL Shortener flows
  • Shorten a URL3 steps
  • Resolve short URL (cache hit)3 steps
  • Resolve short URL (cache miss)4 steps
  • Redis is down4 steps