DJames617 Service Comparison
Multi-AZ vs Read Replica
High availability and read scaling are different goals.
What They Have in Common
Each option can solve part of the scenario. The exam expects you to choose the one that satisfies the stated constraints with the right operational burden, security boundary, availability model, and cost behavior.
Key Differences
| Option | Primary model | Best use | Security | Availability | Operations and cost |
|---|---|---|---|---|---|
| Multi-AZ | Failover availability | Standby/cluster failover for outage resilience | Service-managed standby and encryption controls | Designed for AZ failure and automatic failover | Higher cost for resilience; limited read scaling |
| Read replica | Read scaling and reporting | Offload reads, DR option, cross-Region possible | Replica access and encryption follow service controls | Replica adds read availability; promotion/failover varies | Pays for replica capacity; manage lag and promotion |
Typical Exam Clues
Practice After Studying
Return to the certification guide that includes this comparison and launch domain training from there.