A municipality wants a resilient stack for a public website: web tier that can lose instances, a relational database that survives AZ loss, and object storage that can recover in another Region. Which composition best fits?
Select an answer to reveal the explanation.
Short Explanation
Stateless web plus Multi-AZ Aurora plus S3 CRR is the municipal triple play: instances can die, the DB fails over, and objects have a Regional twin. Parking state on one box undoes all of that. Build the stack from HA building blocks, not nostalgia for one server.
Full Explanation
A municipality that wants a resilient public website needs complementary patterns at each tier: a web tier that can lose instances, a relational database that survives Availability Zone loss, and object storage that can recover in another Region. A strong composition is a stateless web tier, Amazon Aurora with Multi-AZ, and Amazon S3 with cross-Region replication. Stateless web servers can be replaced by Auto Scaling; Aurora Multi-AZ provides synchronous standby failover within the Region; S3 CRR gives object copies in a second Region for Regional recovery of static and uploaded content.
Stateful web servers with local disks, a single-AZ RDS instance, and EBS snapshots only in one AZ fails because local state, single-AZ databases, and AZ-local snapshots leave multiple single points of failure. One EC2 web server with self-managed MySQL on the same host and files only on instance store collapses the entire stack onto one machine. Containers pinned to one AZ with DynamoDB Local on disk and Glacier Vault Lock in a single Region with no replica plan fail as an HA story: Local and single-AZ pinning are not Multi-AZ managed durability, and Glacier alone is not a warm Regional website recovery design.
Exam caveat: Multi-AZ Aurora addresses AZ failure inside a Region; CRR addresses object Regional copies—you still need a Regional compute plan for full site failover. Operational check: verify web ASG spans AZs, Aurora shows Multi-AZ, S3 replication metrics are healthy, and run both AZ and Regional game days for the public site.