DBS-C01 Management and Operations Practice Question
Exhibit
Refer to the exhibit. Exhibit: CloudWatch Logs snippet ``` 2023-01-15T12:00:00Z [ERROR] [Client] Authentication failed for user 'app_user' from host '10.0.1.50' using password 2023-01-15T12:00:01Z [ERROR] [Client] Authentication failed for user 'app_user' from host '10.0.1.50' using password 2023-01-15T12:00:02Z [ERROR] [Client] Authentication failed for user 'app_user' from host '10.0.1.50' using password ```
A database administrator sees the above error logs in CloudWatch for an Amazon RDS for PostgreSQL DB instance. The application team confirms that the password for 'app_user' is correct. What is the most likely cause of the authentication failures?
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 host '10.0.1.50' is not listed in the pg_hba.conf file.
The errors show authentication failures from a specific host. If the password is correct, the most likely cause is that the host is not allowed by the pg_hba.conf configuration. RDS for PostgreSQL uses DB parameter groups to control pg_hba.conf rules; the rds.force_ssl parameter or the pg_hba.conf entries may not include that host.
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 has expired for 'app_user'.
Why it's wrong here
Password expiry would cause a different error message.
- ✗
The user 'app_user' does not have the LOGIN privilege.
Why it's wrong here
A LOGIN privilege issue would result in a different error.
- ✓
The host '10.0.1.50' is not listed in the pg_hba.conf file.
Why this is correct
RDS for PostgreSQL uses pg_hba.conf entries to allow client connections; if the host is not allowed, authentication fails despite correct password.
- ✗
The database is in read-only mode.
Why it's wrong here
Read-only mode does not affect authentication.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
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