Configuring Exponential Backoff Retry in ADF Activities
You have an Azure Data Factory pipeline that copies data from an FTP server to Azure Blob Storage. The pipeline runs successfully most of the time, but occasionally fails with a 'FTP server connection refused' error during peak hours. You need to minimize these failures with minimal cost. What should you do?
⚠ Common exam trap
The trap is choosing an infrastructure or protocol change (ExpressRoute, SFTP) for what is a transient, intermittent error — the exam rewards the minimal-cost, built-in retry mechanism.
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
✓
Add a retry policy to the copy activity with a backoff interval.
A retry policy with a backoff interval on the copy activity handles transient 'connection refused' errors during peak hours by automatically reattempting after a delay, smoothing over temporary FTP server saturation. It is the lowest-cost, least-invasive fix and directly targets intermittent failures without infrastructure changes.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Add a retry policy to the copy activity with a backoff interval.
Why this is correct
Transient connection refusals during peak load are best absorbed by retry logic. A retry policy with backoff interval reattempts the copy activity after progressively longer waits, resolving intermittent FTP failures at negligible cost and no infrastructure changes.
- ✗
Set up Azure ExpressRoute to improve network reliability.
Why it's wrong here
ExpressRoute provides dedicated private connectivity between on-premises networks and Azure, but the FTP server here is external and reached over the public internet, so ExpressRoute cannot carry that traffic and the connection-refused errors persist. It is tempting because ExpressRoute genuinely improves reliability for hybrid workloads, and would be correct if the FTP source sat in a private datacentre linked to Azure.
- ✗
Migrate the FTP server to SFTP.
Why it's wrong here
Migrating to SFTP does not address the transient connection refusals, which stem from the FTP server's concurrent connection limit being exceeded during peak load; SFTP changes the transfer protocol, not that capacity ceiling. It is tempting because SFTP encrypts credentials and data in transit, making it the right choice when the requirement is secure file transfer rather than availability.
- ✗
Increase the parallel copy count in the copy activity.
Why it's wrong here
Raising the parallel copy count increases concurrent connections to the FTP server, worsening the refusals during peak hours. It would suit copying many independent files where the source tolerates higher concurrency, not a connection-limited FTP endpoint.
Quick reference
Azure Blob Storage Tier Comparison
| Tier | Storage Cost | Retrieval Cost | Latency | Use Case |
|---|---|---|---|---|
| Hot | Highest | Lowest | Immediate | Active data, frequent reads |
| Cool | Lower | Higher | Immediate | Data accessed < once / month |
| Cold | Lower still | Higher | Immediate | Data accessed < once / quarter |
| Archive | Lowest | Highest + rehydration delay | Hours | Long-term compliance retention |
Go deeper
Related to this question
Learn chapter
Implement Azure Data Factory Pipelines
Key term
Data Transformation Pipelines
Data transformation pipelines are automated sequences of steps that take raw data from a source, clean and reshape it into a usable format, and then load it into a destination for analysis or storage.
Key term
Azure Data Factory
Azure Data Factory is a cloud-based data integration service that lets you create, schedule, and orchestrate data pipelines to move and transform data from various sources to destinations.
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Microsoft exam blueprint
This DP-203 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-203 exam.