Business continuity questions in the AZ-305 exam often require you to choose the right resiliency strategy based on RTO, RPO, and cost. Since Azure offers multiple overlapping options (Backup, ASR, Geo-redundancy, HA zones), candidates often get confused.
This capsule highlights common pitfalls, decision rules, and exam strategies.
Common Pitfalls
1. Confusing HA with DR
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HA = protection against local failures (zones, load balancers).
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DR = protection against regional disasters (ASR, geo-replication).
Exam Trap: If scenario mentions regional outage, the answer is DR, not just Availability Zones.
2. Backup vs Replication
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Backup = point-in-time recovery, historical snapshots.
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Replication = near real-time copies, low RPO.
Exam Trap: If compliance requires 7 years of retention, the answer is Backup, not ASR.
3. GRS vs RA-GRS
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GRS = data replicated to paired region (no read).
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RA-GRS = adds read access to secondary.
Exam Trap: If requirement is read during outage, choose RA-GRS, not GRS.
4. SQL Geo-Replication vs Auto-Failover Groups
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Geo-replication = manual failover.
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Auto-failover = automatic redirection.
Exam Trap: If downtime must be minimized, answer is Auto-Failover Group.
5. Traffic Manager vs Front Door
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Traffic Manager = DNS-based global failover.
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Front Door = edge-based acceleration + failover.
Exam Trap: If requirement is low-latency global user experience, answer is Front Door, not Traffic Manager alone.
Exam Strategies
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Always match solution to RTO/RPO
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Low RTO + low RPO = ASR, SQL failover groups, Cosmos DB.
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High RTO + high RPO (not urgent) = Backup only.
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Think in layers
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HA within region (Zones, Load Balancer).
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DR across regions (ASR, GRS, Traffic Manager).
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Backup for long-term data retention.
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Compliance & Cost
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Critical apps → multi-region failover, low RTO.
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Non-critical apps → backup + single region HA.
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Don’t over-engineer — align to business criticality.
Quick Recall Table
| Requirement | Best Solution |
|---|---|
| Protect against rack/datacenter fail | Availability Zones |
| Recover from region outage | ASR / Geo-replication |
| Long-term data retention | Azure Backup |
| Read from secondary storage | RA-GRS |
| SQL auto-failover | Auto-Failover Groups |
| Global DNS-based failover | Traffic Manager |
| Low-latency global routing | Front Door |
Exam Tips
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If the question mentions 7+ year retention → Backup (long-term policy).
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If requirement is multi-region active-active writes → Cosmos DB.
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If requirement is minimal downtime auto-failover for SQL → Auto-Failover Groups.
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If requirement is regional failover for VMs → ASR.
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If requirement is compliance: data must never leave EU → Paired region inside EU only.
What to Expect in the Exam
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Direct Q: “Which feature ensures point-in-time recovery for Azure VMs?” → Azure Backup.
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Scenario Q: “Bank requires failover across regions with RPO < 5 min.” → ASR.
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Scenario Q: “Company requires SQL DB to automatically redirect clients during failover.” → Auto-Failover Groups.
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Trick Q: “Availability Zones protect against regional disasters.” → False.