Exam AWS Certified Solutions Architect - Associate SAA-C02 topic 1 question 211 discussion

I think the answer might actually be C, because the transfer is between EC2 instances and not just between S3 and EC2. "Also, be aware of inter-Availability Zones data transfer charges between Amazon EC2 instances, even within the same region. If possible, the instances in a development or test environment that need to communicate with each other should be co-located within the same Availability Zone to avoid data transfer charges. (This doesn’t apply to production workloads which will most likely need to span multiple Availability Zones for high availability.)" https://aws.amazon.com/blogs/mt/using-aws-cost-explorer-to-analyze-data-transfer-costs/

Ans : B You pay for all bandwidth into and out of Amazon S3, except for the following: • Data transferred in from the internet. • Data transferred out to an Amazon Elastic Compute Cloud (Amazon EC2) instance, when the instance is in the same AWS Region as the S3 bucket. • Data transferred out to Amazon CloudFront (CloudFront).

C is the answer

Data Transfer within the same AWS Region Data transferred "in" to and "out" from Amazon EC2, Amazon RDS, Amazon Redshift, Amazon DynamoDB Accelerator (DAX), and Amazon ElastiCache instances, Elastic Network Interfaces or VPC Peering connections across Availability Zones in the same AWS Region is charged at $0.01/GB in each direction.

question stated "minimize the total cost of data transfer?" instead "FREE OF CHARGE". answer is B

I believe it is C. https://aws.amazon.com/blogs/architecture/overview-of-data-transfer-costs-for-common-architectures/ A common pattern is to deploy workloads across multiple VPCs in your AWS network. Two approaches to enabling VPC-to-VPC communication are VPC peering connections and AWS Transit Gateway. Data transfer over a VPC peering connection that stays within an Availability Zone is free. Data transfer over a VPC peering connection that crosses Availability Zones will incur a data transfer charge for ingress/egress traffic (Figure 4).

B is correct but C is incorrect. Is it possible ?

Data transferred between Amazon EC2, Amazon RDS, Amazon Redshift, Amazon ElastiCache instances, and Elastic Network Interfaces in the same Availability Zone is free. https://aws.amazon.com/ec2/pricing/on-demand/

**The program will handle the data by transferring it over the network across different Amazon EC2 instances.** Data transferred "in" to and "out" from Amazon EC2, Amazon RDS, Amazon Redshift, Amazon DynamoDB Accelerator (DAX), and Amazon ElastiCache instances, Elastic Network Interfaces or VPC Peering connections across Availability Zones in the same AWS Region is charged at $0.01/GB in each direction. Data transferred between Amazon EC2, Amazon RDS, Amazon Redshift, Amazon ElastiCache instances, and Elastic Network Interfaces in the same Availability Zone is free.

I go for C.

The data flow: S3 bucket A -> EC2 (to obtain data input) -> EC2-B (to process data) -> S3 bucket B. Data is transferred between two EC2. Thus, C is the answer.

C: https://aws.amazon.com/ec2/pricing/on-demand/#Data_Transfer_within_the_same_AWS_Region Data Transfer within the same AWS Region Data transferred "in" to and "out" from Amazon EC2, Amazon RDS, Amazon Redshift, Amazon DynamoDB Accelerator (DAX), and Amazon ElastiCache instances, Elastic Network Interfaces or VPC Peering connections across Availability Zones in the same AWS Region is charged at $0.01/GB in each direction. Data transferred between Amazon EC2, Amazon RDS, Amazon Redshift, Amazon ElastiCache instances, and Elastic Network Interfaces in the same Availability Zone is free. Data transferred directly (see endpoints) between Amazon S3, Amazon EBS direct APIs*, Amazon Glacier, Amazon DynamoDB, Amazon SES, Amazon SQS, Amazon Kinesis, Amazon ECR, Amazon SNS or Amazon SimpleDB and Amazon EC2 instances in the same AWS Region is free.

Typo, Answer C should be correct.

sorry, the answer A should be correct. Please remove my previous answer.

B seems correct

C is correct - Data transferred between Amazon EC2, Amazon RDS, Amazon Redshift, Amazon ElastiCache instances, and Elastic Network Interfaces in the same Availability Zone is free. - Data transferred "in" to and "out" from Amazon EC2, Amazon RDS, Amazon Redshift, Amazon DynamoDB Accelerator (DAX), and Amazon ElastiCache instances, Elastic Network Interfaces or VPC Peering connections across Availability Zones in the same AWS Region is charged at $0.01/GB in each direction.

q: minimize the total cost of data transfer ans: b. no data transfer cost between eC2 & S3 with in same region. https://aws.amazon.com/s3/pricing/