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198What is Database Replication?
199Primary-Replica Architecture
200Why Replicate: Read Scaling
201Why Replicate: Availability and Failover
202Why Replicate: Geographic Distribution
203Synchronous Replication Explained
204Asynchronous Replication Explained
205Semi-Synchronous Replication
206Replication Logs and Mechanisms
207Replica Promotion and Failover Basics
208Replication Lag: What It Is and Why It Happens
209Read-After-Write Consistency Problem
210Monotonic Reads Guarantee
211Consistent Prefix Reads
212Measuring Replication Lag
213Acceptable Lag Windows by Use Case
214Session-Based Routing for Read-After-Write
215Sticky Sessions and Replica Affinity
216Timestamp-Based Consistency Checks
217Semi-Synchronous Replication Trade-offs
218Lag-Aware Load Balancing
219Application-Level Consistency Patterns
220Read-Write Splitting Fundamentals
221Application-Level Connection Management
222Proxy-Based Read-Write Splitting
223Detecting Read vs Write Queries
224Read-After-Write Consistency
225Sticky Sessions and Primary Reads
226Load Distribution Across Replicas
227Handling Replica Failures in Routing
228Monitoring Read-Write Split Effectiveness

198What is Database Replication?
199Primary-Replica Architecture
200Why Replicate: Read Scaling
201Why Replicate: Availability and Failover
202Why Replicate: Geographic Distribution
203Synchronous Replication Explained
204Asynchronous Replication Explained
205Semi-Synchronous Replication
206Replication Logs and Mechanisms
207Replica Promotion and Failover Basics
208Replication Lag: What It Is and Why It Happens
209Read-After-Write Consistency Problem
210Monotonic Reads Guarantee
211Consistent Prefix Reads
212Measuring Replication Lag
213Acceptable Lag Windows by Use Case
214Session-Based Routing for Read-After-Write
215Sticky Sessions and Replica Affinity
216Timestamp-Based Consistency Checks
217Semi-Synchronous Replication Trade-offs
218Lag-Aware Load Balancing
219Application-Level Consistency Patterns
220Read-Write Splitting Fundamentals
221Application-Level Connection Management
222Proxy-Based Read-Write Splitting
223Detecting Read vs Write Queries
224Read-After-Write Consistency
225Sticky Sessions and Primary Reads
226Load Distribution Across Replicas
227Handling Replica Failures in Routing
228Monitoring Read-Write Split Effectiveness

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Lesson 208 of 1,919·6. Database Scaling: Read ReplicasPro lesson

Replication Lag: What It Is and Why It Happens

Understanding the delay between writes on primary and their appearance on replicas, and the fundamental causes.

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