A mission-critical application stores data in a Standard general-purpose v2 account named storage5, in a region with availability zones. It must keep reading and writing if one availability zone in the primary region fails. During a region-wide outage it must still be able to read data, without anyone performing an account failover. Which redundancy option should you configure?
Show answer and explanation
Correct answer: B · RA-GZRS
RA-GZRS replicates synchronously across three zones in the primary region, so reads and writes continue through a zone failure. It also replicates to a secondary region that applications can read from at any time through the secondary endpoint, with no failover. Secondary replication is asynchronous, so the latest writes may not be there yet.
Why the other choices do not fit
- GZRS survives a zone failure, but its secondary region cannot be read until a failover is performed.
- RA-GRS allows reads from the secondary without failover, but its primary copies are LRS in a single datacenter. A zone failure affecting that datacenter can interrupt writes in the primary region.
- GRS keeps LRS in the primary region and does not expose the secondary for reads until failover, so it fails both requirements.