Question 275 of 919
Plan and configure a high availability and disaster recovery environment →hardMultiple ChoiceObjective-mapped
Zero Data Loss Planned Failover: Set Primary Read-Only Then Failover
Your company has an Azure SQL Database configured with active geo-replication to a secondary region. You need to perform a planned failover for disaster recovery testing with zero data loss. The primary database is under heavy write load. What should you do?
Quick Answer
The correct action is to set the primary database to read-only, perform a planned failover, then switch the new primary to read-write. This ensures zero data loss because setting the primary to read-only blocks any new writes, allowing active geo-replication to catch up and synchronize all committed transactions to the secondary before the failover occurs. On the Microsoft Azure Database Administrator Associate DP-300 exam, this scenario tests your grasp of planned failover mechanics under heavy write load — a common trap is assuming switching the secondary to read-write triggers a failover or that a backup and restore would suffice, both of which risk data loss. The key concept is that geo-replication provides near-real-time synchronization, but pending writes on the primary must be quiesced to achieve zero data loss. Memory tip: “Block, Sync, Switch” — block writes on the primary, let replication sync, then failover and re-enable writes on the new primary.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Set the primary database to read-only, perform a planned failover, then switch the new primary to read-write.
To achieve zero data loss during a planned failover under heavy write load, you should set the primary database to read-only to block any new writes. This allows the geo-replication to catch up and synchronize all committed transactions to the secondary. Then perform the planned failover (which switches the secondary to become the new primary). After failover, set the new primary to read-write mode to resume writes. Option B is incorrect: switching the secondary to read-write only enables read workloads on the secondary; it does not trigger a failover. The failover must be explicitly initiated, and the write-heavy primary still has pending transactions. Option C is incorrect: a full backup and restore would cause data loss because any transactions after the backup would be lost. Geo-replication provides near-real-time synchronization. Option D is incorrect: scaling up the primary does not affect the failover process or guarantee zero data loss. The only way to ensure zero data loss is to prevent writes and synchronize before failover.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Set the primary database to read-only, perform a planned failover, then switch the new primary to read-write.
Why this is correct
Correct: This ensures no writes occur during failover, preserving data.
- ✗
Switch the secondary to read-write mode and then failover.
Why it's wrong here
Incorrect: The secondary is already readable; switching to read-write does not prevent data loss.
- ✗
Take a full backup of the primary, restore it to the secondary, and then failover.
Why it's wrong here
Incorrect: Backup and restore would cause data loss of transactions after the backup.
- ✗
Scale up the primary database to the highest performance tier to handle writes during failover.
Why it's wrong here
Incorrect: Scaling up does not prevent data loss during failover.
Visual reference
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Same concept, more angles
1 more way this is tested on DP-300
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. You manage an Azure SQL Database that uses active geo-replication with a secondary in a paired region. During a planned maintenance, you need to fail over to the secondary with zero data loss. What should you do?
medium- A.Use Azure portal to 'Failover' without specifying data loss tolerance
- B.Take the primary offline, then promote the secondary
- ✓ C.Execute a planned failover (graceful failover) using Transact-SQL or PowerShell
- D.Execute a forced failover allowing data loss
Why C: A planned failover (graceful failover) synchronizes all transactions between the primary and secondary before switching, ensuring zero data loss. Option A uses a standard failover that may allow data loss if the secondary is not fully synchronized. Option B causes data loss by taking the primary offline abruptly. Option D explicitly allows data loss, which is not acceptable for this requirement.
Last reviewed: Jun 21, 2026
This DP-300 practice question is part of Courseiva's free Microsoft certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the DP-300 exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.