An architect notices high inter-AZ data transfer charges between application instances and their database. The workload doesn’t require cross-AZ separation for these chatty components. How can transfer costs be reduced while keeping reasonable resilience overall?
A) Place tightly-coupled, chatty components in the same AZ, while keeping the broader architecture multi-AZ.
B) Move all components to different regions.
C) Route all internal traffic through a NAT Gateway.
D) Enable cross-region replication for the database.
Correct Answer: A
Explanation: Data transferred between AZs incurs charges, while same-AZ traffic is cheaper; co-locating chatty components in one AZ reduces cost, and overall resilience is preserved by keeping the broader architecture multi-AZ. (B) cross-region transfer is even more expensive. (C) NAT Gateways are for internet egress and add cost. (D) replication increases transfer.