Conflict Resolution Policy
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Category: Data Distribution & Consistency
Summary: Defines how concurrent multi-region write conflicts are resolved (e.g., LWW).
Overview
A conflict resolution policy defines how Azure Cosmos DB for NoSQL resolves write conflicts that occur when multi-region writes are enabled and the same item is updated concurrently in different regions. Options include Last-Writer-Wins (LWW, based on a numeric property, defaulting to timestamp), or a custom conflict resolution stored procedure for application-specific merge logic.
More Info & Links
DP-420 Style Practice Questions
Q1. Which built-in conflict resolution policy resolves conflicts based on a numeric property, defaulting to the write timestamp?
- A. Last-Writer-Wins (LWW)
- B. First-Writer-Wins
- C. Manual resolution only
- D. Round-robin resolution
Q2. How can you implement custom, application-specific logic for resolving write conflicts?
- A. By implementing a custom conflict resolution stored procedure
- B. By disabling multi-region writes entirely
- C. By setting the consistency level to Strong
- D. By enabling TTL on the container
Answer Key
Answers are listed at the very end so you can attempt the questions first.
- Q1 (Conflict Resolution Policy): A. Last-Writer-Wins (LWW) — Last-Writer-Wins (LWW) resolves conflicts using a numeric property, defaulting to the system timestamp if none is specified.
- Q2 (Conflict Resolution Policy): A. By implementing a custom conflict resolution stored procedure — A custom conflict resolution stored procedure allows you to implement your own merge/resolution logic for conflicting writes.
DP-420: Designing and Implementing Cloud-Native Applications Using Microsoft Azure Cosmos DB — term detail page
