You added read replicas to scale reads. Now users update their profile and see the old version. Welcome to replica lag.
Posts for: #Consistency
Cache Invalidation: The Hard Problem
There are only two hard things in computer science: cache invalidation and naming things. Here’s why invalidation is so tricky, and what actually works.
Vector Clocks and Lamport Timestamps
How distributed systems track ‘what happened before what’ without trusting wall clocks. Lamport timestamps for ordering, vector clocks for detecting conflicts.
Session Guarantees: The Promises Your Database Makes to You
Read-your-writes and monotonic reads aren’t just buzzwords. They’re the difference between a database that feels broken and one that makes sense to users.
Read Repair and Anti-Entropy: Healing Stale Replicas
How do stale replicas catch up in distributed systems? Compare read repair and anti-entropy strategies with Merkle trees for healing data divergence.
Consistency Models: What Eventually Means
Eventual consistency doesn’t mean milliseconds. Understand linearizability, causal consistency, and quorum reads to pick the right consistency model.