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CAP Theorem & Consistency Models

Difficulty: Medium | Topic #13

What to Learn​

CAP theorem tradeoffs (Consistency, Availability, Partition Tolerance), strong consistency vs eventual consistency, read-your-writes, monotonic reads, linearizability, when to choose AP vs CP systems.

Resources​

Covered by Problems​

ProblemDifficultyLink
Distributed CacheMedium→
Ticketing System (Ticketmaster)Medium→
Online AuctionMedium→
Payment SystemHard→
Real-time Doc Collaboration (Google Docs)Hard→

Key Concepts to Master​

  • Why partition tolerance is mandatory in distributed systems
  • CP vs AP design choices and examples (HBase vs Cassandra)
  • Eventual consistency models (read-your-writes, monotonic reads, causal consistency)
  • Linearizability vs serializability
  • PACELC theorem as a more nuanced view