Question 1hardmultiple choice
Full question →hardmultiple choiceObjective-mapped
You are developing an Azure Function that runs on a Consumption Plan. The function calls an external API that enforces a rate limit of 10 requests per second. When the function scales out to multiple instances, you must ensure the rate limit is not exceeded. Which pattern should you implement?
Answer choices
Why each option matters
Good practice is not just finding the correct option. The wrong answers often show the exact trap the exam wants you to fall into.
A
Distractor review
Use a singleton attribute on the function to ensure only one instance runs.
Singleton limits concurrency to one instance but does not control the rate of calls to an external API; the single instance could still exceed the rate limit.
B
Distractor review
Use a static SemaphoreSlim in the function code to limit concurrent calls.
Static variables are not shared across instances in a distributed scale-out environment.
C
Distractor review
Configure the function's host.json to limit concurrency to 1.
This limits concurrent function executions but does not enforce a per-second rate; a single instance can still call the API more than 10 times per second.
D
Best answer
Use a queue-based load leveling pattern with an Azure Storage Queue.
Messages are queued, and a function processes them at a controlled rate (e.g., using a timer or batching) to respect the API's rate limit, regardless of the number of instances.
Common exam trap
Common exam trap: NAT rules depend on direction and matching traffic
NAT is not only about the public address. The inside/outside interface roles and the ACL or rule that matches traffic are just as important.
Technical deep dive
How to think about this question
NAT questions usually test address translation, overload/PAT behaviour, static mappings and whether the right traffic is being translated. Read the interface direction and address terms carefully.
KKey Concepts to Remember
- Static NAT maps one inside address to one outside address.
- PAT allows many inside hosts to share one public address using ports.
- Inside local and inside global describe the private and translated addresses.
- NAT ACLs identify traffic for translation, not always security filtering.
TExam Day Tips
- Identify inside and outside interfaces first.
- Check whether the scenario needs static NAT, dynamic NAT or PAT.
- Do not confuse NAT matching ACLs with normal packet-filtering intent.
Related practice questions
Related AZ-204 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
More questions from this exam
Keep practising from the same exam bank, or move into a focused topic page if this question exposed a weak area.
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Question 5
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Question 6
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FAQ
Questions learners often ask
What does this AZ-204 question test?
Static NAT maps one inside address to one outside address.
What is the correct answer to this question?
The correct answer is: Use a queue-based load leveling pattern with an Azure Storage Queue. — Queue-based load leveling decouples the function from the external API by using a storage queue. The function writes messages to the queue, and a separate process (or a function with limited concurrency) dequeues and calls the API at a controlled rate. This works across multiple instances. Singleton limits execution to one instance but does not control rate per second. Static semaphores do not work across instances. Concurrency throttling controls concurrent executions but does not enforce a per-second rate limit.
What should I do if I get this AZ-204 question wrong?
Then try more questions from the same exam bank and focus on understanding why the wrong options are tempting.
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