Data transfer costs within a region

Data transfer costs within a region

SabaLal updated 2 years, 2 months ago 2 Members · 3 Posts
AWS Certified Solutions Architect Associate
SabaLal

Member
July 22, 2022 at 1:13 pm

Hi there, came across one of your questions:

7. QUESTION

A company plans to design an application that can handle batch processing of large amounts of financial data. The Solutions Architect is tasked to create two Amazon S3 buckets to store the input and output data. The application will transfer the data between multiple EC2 instances over the network to complete the data processing.

Which of the following options would reduce the data transfer costs?

<ul data-question_id=”8662″ data-type=”single”>
Deploy the Amazon EC2 instances in the same AWS Region
Deploy the Amazon EC2 instances in the same Availability Zone.

The correct answer is indicated as #2 (within same AZ)

Explanation states that:

The option that says: Deploy the Amazon EC2 instances in the same AWS Region is incorrect because even if the instances are deployed in the same Region, they could still be charged with inter-Availability Zone data transfers if the instances are distributed across different availability zones. You must deploy the instances in the same Availability Zone to avoid the data transfer costs.

However AWS documentation states:

ata 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.

Based on the Q, there are no additional services that may incur a charge for intra-region data transfer. Could you pls confirm?