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Monitoring and TroubleshootinghardMultiple ChoiceObjective-mapped

DBS-C01 Monitoring and Troubleshooting Practice Question

Exhibit

Refer to the exhibit.

From Amazon CloudWatch Logs:

2023-04-01T12:00:00Z [ERROR] [Client] Authentication failed for user 'app_user' from host '10.0.1.50' using method 'mysql_native_password'
2023-04-01T12:01:00Z [ERROR] [Client] Access denied for user 'app_user'@'10.0.1.50' (using password: YES)
2023-04-01T12:02:00Z [ERROR] [Client] Access denied for user 'app_user'@'10.0.1.50' (using password: YES)

A database engineer is reviewing Amazon RDS for MySQL error logs and sees repeated authentication failures from the same IP address. The application team confirms the password is correct. What is the most likely cause of these errors?

⚠ Common exam trap

Many candidates assume authentication failures always mean a wrong password, but AWS/DBS-C01 tests your understanding that MySQL's host-based authentication can produce the same error message when the host is not authorized, even with a valid password.

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 user 'app_user' does not have access from host '10.0.1.50'

The error logs show authentication failures despite the password being correct, which indicates the issue is not with the password itself but with the host-based access control. In MySQL, user accounts are defined as 'user'@'host', and if the application is connecting from an IP address (e.g., 10.0.1.50) that is not included in the user's allowed hosts, MySQL will reject the connection with an authentication error even if the password is correct. This is a common misconfiguration when migrating or scaling applications across different subnets.

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 password is incorrect

    Why it's wrong here

    The application team confirmed the password is correct.

  • The user 'app_user' does not have access from host '10.0.1.50'

    Why this is correct

    The user may be defined as 'app_user'@'%' or from a different host, causing a mismatch.

  • The 'app_user' account is locked

    Why it's wrong here

    A locked account would show a different error.

  • The database requires SSL connections

    Why it's wrong here

    SSL requirement would show a different error.

Visual reference

192.168.1.0 /24 256 addresses (254 usable) 192.168.1.0 /25 Subnet A 128 addr (126 usable) 192.168.1.128 /25 Subnet B 128 addr (126 usable) Borrowing 1 bit from host portion creates 2 subnets (/25)

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JA

Written by Johnson Ajibi, MSc IT Security

Senior Network & Security Engineer · founder of Courseiva

This DBS-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 DBS-C01 exam.