Cap Theorem medium
In an AP system with multi-master replication, what is an inevitable side effect?
- A The creation of a Single Point of Failure that can crash the entire system during a peak traffic window.
- B Inherently slow read performance because the system must query every node in the cluster to find the truth.
- C Write Conflicts, where two different nodes accept different data for the same key at the exact same time.
- D The requirement that all incoming data must be encrypted with a public-key infrastructure (PKI) at rest.
Answer: C. Write Conflicts, where two different nodes accept different data for the same key at the exact same time.
In an AP system where 'anyone can write to any node', concurrent updates are a natural consequence of prioritizing availability. If Node A and Node B both accept updates for the same record during a partition, they will eventually have divergent data. This is often called a 'Conflict'. The system must then use a resolution strategy like 'Last-Write-Wins', 'Vector Clocks', or 'CRDTs' to reconcile these differences once the partition clears.
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