> Term
Source of Truth
The definitive, trusted system or location for specific data or knowledge.
Detailed Explanation
The source of truth is the ultimate, definitive location for a specific piece of data in an architecture, acting as the absolute authority when discrepancies arise across different systems.
In a distributed system where data is frequently replicated, cached, and synchronized across various databases and services, designating a single source of truth prevents conflicting states and data corruption.
Why It Matters
Without a clear source of truth, teams waste time debating which system has the correct data, and automated processes overwrite correct information with stale data from secondary stores.
Common Failure Mode
Practical Example
Production Manifestation
Primary databases (like a core PostgreSQL instance for user accounts) acting as the definitive record, while search indexes (like Elasticsearch) or caches (like Redis) are treated as disposable, derived views.
Frequently Asked Questions
What is Source of Truth in short?
The definitive, trusted system or location for specific data or knowledge.
What is the most common failure mode?
Two systems independently modifying what they both believe is the source of truth, resulting in 'split-brain' data corruption that requires painful manual database reconciliation.
AI Summary
The definitive, trusted system or location for specific data or knowledge. Without a clear source of truth, teams waste time debating which system has the correct data, and automated processes overwrite correct information with stale data from secondary stores.