The answer is a memory leak in the custom inference code. This is the most likely cause because a memory leak gradually consumes available memory over the duration of a single batch transform job, eventually triggering an out-of-memory error even when the dataset size remains unchanged. On the AWS Certified Machine Learning Engineer Associate MLA-C01 exam, this question tests your understanding of how custom code execution within SageMaker containers can degrade performance over time, a common trap where candidates mistakenly blame instance type or data volume. The key insight is that sporadic failures in long-running jobs often point to resource accumulation in user-written logic rather than static infrastructure issues. Remember the mnemonic: "Leaks are sneaky, not spikey"—a memory leak builds slowly, while a sudden OOM usually indicates a data spike or undersized instance.
MLA-C01 Practice Question: ML Solution Monitoring, Maintenance and Security
This MLA-C01 practice question tests your understanding of ml solution monitoring, maintenance and security. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A company has a batch transform job in Amazon SageMaker that processes large datasets every night. Recently, the job has been failing sporadically with an out-of-memory error. The data size has not increased. What is the MOST likely cause?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "most likely"
Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The custom inference code has a memory leak that gradually consumes available memory.
Option D is correct because a memory leak in custom code would cause increasing memory usage over time within a single job, leading to OOM. Option A is wrong because instance type is fixed; if it worked before, instance type is not the issue. Option B is wrong because if the data size hasn't increased, total data is not the cause. Option C is wrong because data distribution change doesn't directly cause OOM; it might cause different processing but not necessarily memory exhaustion.
Key principle: NAT direction and interface roles matter as much as the IP address mapping. Inside/outside designation controls which traffic is translated.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✓
The custom inference code has a memory leak that gradually consumes available memory.
Why this is correct
A memory leak can cause OOM even with same data size.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Static NAT maps one inside address to one outside address.
✗
The data distribution has shifted, causing different memory usage patterns.
Why it's wrong here
While possible, it's less likely than a code issue; OOM typically from code.
✗
The instance type is not large enough to handle the dataset.
Why it's wrong here
Data size hasn't increased, so if it worked before, instance type is sufficient.
✗
The batch transform input data has increased in size.
Why it's wrong here
The question states data size has not increased.
Common exam traps
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.
Detailed technical explanation
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.
Key takeaway
NAT direction and interface roles matter as much as the IP address mapping. Inside/outside designation controls which traffic is translated.
Real-world example
How this comes up in practice
A cloud solutions architect for a retail company is evaluating services for a new workload. The correct answer here reflects best practice for the specific scenario described — not a general cloud recommendation. NAT direction and interface roles matter as much as the IP address mapping. Inside/outside designation controls which traffic is translated. Cloud exam questions reward reading the constraint carefully: the same technology can be right or wrong depending on the use case.
What to study next
Got this wrong? Here's your next step.
Review the four NAT address types (inside local, inside global, outside local, outside global), PAT port overload, and static vs dynamic NAT use cases. Then practise related MLA-C01 NAT questions on configuration and troubleshooting.
ML Solution Monitoring, Maintenance and Security — This question tests ML Solution Monitoring, Maintenance and Security — Static NAT maps one inside address to one outside address..
What is the correct answer to this question?
The correct answer is: The custom inference code has a memory leak that gradually consumes available memory. — Option D is correct because a memory leak in custom code would cause increasing memory usage over time within a single job, leading to OOM. Option A is wrong because instance type is fixed; if it worked before, instance type is not the issue. Option B is wrong because if the data size hasn't increased, total data is not the cause. Option C is wrong because data distribution change doesn't directly cause OOM; it might cause different processing but not necessarily memory exhaustion.
What should I do if I get this MLA-C01 question wrong?
Review the four NAT address types (inside local, inside global, outside local, outside global), PAT port overload, and static vs dynamic NAT use cases. Then practise related MLA-C01 NAT questions on configuration and troubleshooting.
Are there clue words in this question I should notice?
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
What is the key concept behind this question?
Static NAT maps one inside address to one outside address.
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 →
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.
This MLA-C01 practice question is part of Courseiva's free Amazon Web Services 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 MLA-C01 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.