DEA-C01 Data Operations and Support Practice Question
A data engineering team is troubleshooting a failing AWS Glue ETL job that processes data from an S3 bucket. The job writes output to another S3 bucket. The job fails with an AccessDenied error when writing to the output bucket. The IAM role used by the job has the following policy attached: {"Version":"2012-10-17","Statement":[{"Effect":"Allow","Action":["s3:GetObject","s3:ListBucket"],"Resource":["arn:aws:s3:::input-bucket/*","arn:aws:s3:::input-bucket"]}]}. What is the most likely cause of the failure?
⚠ Common exam trap
The trap here is that candidates focus on the input bucket permissions (which are present) and overlook that write operations require a completely separate s3:PutObject action that is absent from the policy.
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
✓
The IAM role does not have s3:PutObject permission on the output bucket.
The IAM policy attached to the Glue job role only grants s3:GetObject and s3:ListBucket on the input bucket. There is no s3:PutObject (or any write) permission on the output bucket, so when Glue attempts to write results, S3 returns AccessDenied. The most likely cause is therefore the missing write permission on the output bucket.
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 ETL job is processing more than 10 TB of data.
Why it's wrong here
The attached policy grants only s3:GetObject and s3:ListBucket on the input bucket, so writing to the output bucket fails because s3:PutObject is absent from the role. Data volume is irrelevant; AccessDenied stems from missing write permissions, not from processing more than 10 TB.
- ✗
The output bucket has a bucket policy that denies access to the IAM role.
Why it's wrong here
The attached identity policy grants only s3:GetObject and s3:ListBucket on input-bucket, so no statement permits s3:PutObject on the output bucket; an explicit deny is not required for AccessDenied. It is tempting because bucket policies can deny access, and they are the right control when restricting cross-account or public S3 access.
- ✓
The IAM role does not have s3:PutObject permission on the output bucket.
Why this is correct
The attached policy grants only s3:GetObject and s3:ListBucket on the input bucket. Writing objects requires s3:PutObject, which is absent for the output bucket, so S3 returns AccessDenied. Adding s3:PutObject on the output bucket's ARN resolves the failure.
- ✗
The IAM role used by the job does not exist.
Why it's wrong here
A non-existent role would prevent the Glue job from starting at all, producing a role-assumption or entity-not-found error rather than AccessDenied on a PutObject call. It is tempting because missing roles do cause job failures, and creating a dedicated IAM role is the correct setup when configuring a new Glue job.
Quick reference
AWS S3 Storage Class Comparison
| Storage Class | Min Duration | Retrieval | Use Case |
|---|---|---|---|
| S3 Standard | None | Immediate | Frequently accessed data |
| S3 Standard-IA | 30 days | Immediate | Infrequent access, rapid retrieval |
| S3 One Zone-IA | 30 days | Immediate | Non-critical infrequent data |
| S3 Intelligent-Tiering | None | Immediate–hours | Unknown or changing access patterns |
| S3 Glacier Instant | 90 days | Milliseconds | Archive with instant retrieval |
| S3 Glacier Flexible | 90 days | Minutes–hours | Archive, flexible retrieval |
| S3 Glacier Deep Archive | 180 days | Hours | Long-term compliance archive |
Go deeper
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Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Amazon Web Services exam blueprint
This DEA-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 DEA-C01 exam.