Question 1easymultiple choice
Full question →easymultiple choiceObjective-mapped
A developer wants to store session state data for a web application running on multiple EC2 instances behind an Application Load Balancer. The data is ephemeral and should not persist if an instance is terminated. Which storage option should the developer use?
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
Best answer
Amazon ElastiCache
Correct. ElastiCache provides an in-memory cache that is ephemeral (by default) and can be shared across all EC2 instances, making it ideal for session state in a distributed environment.
B
Distractor review
Amazon RDS
Incorrect. RDS is a relational database that provides persistent storage. Session state data does not need to survive instance termination; using RDS would be unnecessary for the stated requirement and slower than in-memory caching.
C
Distractor review
Amazon S3
Incorrect. S3 is object storage with higher latency and is not designed for ephemeral session state. It is also not automatically cleaned up when a session ends without explicit deletion.
D
Distractor review
Amazon EFS
Incorrect. EFS provides persistent file storage that can be mounted on multiple instances. While it can be used for session state, it is not ephemeral; data persists after instance termination, which is not desired in this scenario.
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 DVA-C02 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.
Question 1
A developer is building a REST API using Amazon API Gateway that will serve static content from an Amazon S3 bucket. The API should cache responses for frequently accessed objects to reduce latency. Which API Gateway feature should the developer enable?
Question 2
A developer is running a web application on multiple Amazon EC2 instances behind an Application Load Balancer (ALB). The application needs to store user session state that must be available across all instances. The session data is small and temporary but must survive individual instance failures. Which AWS service should the developer use to store this session state?
Question 3
A developer has an AWS Lambda function that processes messages from an Amazon SQS standard queue. The function is idempotent and currently has a batch size of 10. The developer wants to increase throughput and increases the batch size to 100. After the change, CloudWatch metrics show a significant increase in throttles and the queue backlog is growing. The function's reserved concurrency is set to 10. What is the most effective action to resolve the throttling and improve throughput?
Question 4
A developer is managing an application running on Amazon EC2 instances behind an Application Load Balancer. Users report that the application becomes unresponsive after several hours, and restarting the instance temporarily fixes the issue. The developer suspects a memory leak but cannot add custom instrumentation. Which AWS service can collect memory utilization metrics and help identify the memory leak with minimal configuration?
Question 5
A developer is building a serverless web application using AWS Lambda and Amazon DynamoDB. The application needs to perform complex aggregations on data stored in DynamoDB. Which AWS service should the developer use to perform these aggregations efficiently without reading all the data into Lambda?
Question 6
A developer has an Amazon S3 bucket containing private user documents. The application must generate a time-limited URL for users to download their own documents without requiring the users to have AWS credentials. Which solution should the developer use?
FAQ
Questions learners often ask
What does this DVA-C02 question test?
Static NAT maps one inside address to one outside address.
What is the correct answer to this question?
The correct answer is: Amazon ElastiCache — For ephemeral session state that should be shared across instances but not persist beyond the session lifetime, an in-memory cache like Amazon ElastiCache (Memcached or Redis) is ideal. It provides low-latency access and automatically evicts data when the instance is terminated or the session expires. Other options like EFS or RDS provide persistent storage, which is not required and may add unnecessary cost.
What should I do if I get this DVA-C02 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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