DBS-C01 Deployment and Migration Practice Test 12 — 15 Questions

Question 1

A company is migrating a MySQL database to Amazon Aurora MySQL. The migration must be completed with minimal downtime. Which TWO methods can achieve this? (Choose two.)

Accepted Answer

Create an Aurora MySQL read replica from the external MySQL instance using binlog replication. You can set up an external MySQL instance as a replication source for an Amazon Aurora MySQL read replica using binary log (binlog) replication. This allows the Aurora cluster to stay synchronized with the source database with minimal downtime, as you only need to stop writes on the source and promote the Aurora replica when ready. Option D is correct because AWS Database Migration Service (AWS DMS) supports ongoing replication using change data capture (CDC) to keep the target Aurora database continuously synchronized with the source MySQL database, enabling a migration with minimal downtime. Options B, C, and E are incorrect: taking a physical backup and restoring (B) or creating an Aurora clone from the source (C) would require downtime; enabling binlog replication alone (E) is not sufficient—it must be used with a replication setup or a service like DMS.

Answer

Take a physical backup of the source database and restore to Aurora

Answer

Create an Aurora clone from the source database

Answer

Enable binlog replication on the source MySQL instance

Question 2

A company is migrating a 3 TB PostgreSQL database from on-premises to Amazon RDS for PostgreSQL. The migration must have minimal downtime. The on-premises network bandwidth to AWS is 1 Gbps. The database supports a critical application that cannot be stopped for more than 30 minutes. The migration team has set up AWS DMS with ongoing replication using CDC. The initial full load is expected to take 8 hours. During the migration, the DMS task fails with an error indicating that the source database's transaction log is being cleaned before DMS can capture changes. The source database has a transaction log retention period of 24 hours. The migration team notices that the CDC phase falls behind during peak hours. What should the team do to complete the migration successfully within the downtime window?

Accepted Answer

Increase the transaction log retention period on the source database and use a larger DMS replication instance. The issue is that DMS cannot keep up with changes during peak hours, causing the transaction logs to be cleaned before DMS reads them. Increasing the source database's transaction log retention period gives DMS more time to catch up. Using a larger DMS replication instance will increase processing capacity. Option C is the best combination. Option A (Snowball) would take too long. Option B (Direct Connect) doesn't solve the log retention issue. Option D (decrease retention) makes the problem worse.

Answer

Use AWS Snowball to transfer the full database and then use DMS for CDC

Answer

Increase the network bandwidth using AWS Direct Connect

Answer

Decrease the transaction log retention period to free up space

Question 3

A company is deploying a new web application on AWS. The application uses Amazon RDS for MySQL as its database. The database must be highly available and automatically failover in the event of an AZ outage. The company also needs to offload read traffic from the primary database to improve performance. The application read-to-write ratio is 80:20. The database workload is variable, with occasional spikes. The company wants a cost-effective solution that scales read capacity automatically. The operations team has limited experience with AWS. Which solution should the company implement?

Accepted Answer

Deploy an Amazon Aurora MySQL cluster with Multi-AZ and enable Aurora Auto Scaling for read replicas. This solution is correct because Amazon Aurora is MySQL-compatible, provides high availability and automatic failover through its Multi-AZ deployment, and includes Aurora Auto Scaling which automatically adjusts the number of read replicas based on workload, scaling read capacity automatically. This is cost-effective as you pay only for the replicas you use and it requires minimal management, making it ideal for teams with limited AWS experience. Option A is incorrect because read replicas do not auto-scale automatically; Application Auto Scaling for replicas requires custom setup. Option B is incorrect because scaling instance size does not offload read traffic or provide read scaling. Option D is incorrect because it lacks automatic failover and requires manual intervention.

Answer

Deploy an RDS for MySQL instance with Multi-AZ and one or more read replicas, and use Application Auto Scaling to add replicas based on CPU utilization

Answer

Deploy an RDS for MySQL instance with Multi-AZ and enable automatic scaling of the instance size

Answer

Deploy an RDS for MySQL instance with multiple read replicas and use a custom script to promote a read replica in case of failure

Question 4

A company is migrating a 500 GB Oracle database to Amazon RDS for Oracle. The migration must be completed within 24 hours with minimal downtime. The on-premises network bandwidth is 1 Gbps. The migration team plans to use AWS DMS with ongoing replication. During the initial load, the DMS task fails with an error indicating that the source database is experiencing high CPU utilization. The source database is a production system serving live traffic. The team needs to reduce the impact on the source database while still meeting the migration deadline. Which approach should the team take?

Accepted Answer

Reduce the number of tables loaded in parallel in the DMS task and schedule the migration during off-peak hours. The issue is that DMS is consuming too many resources on the source. Reducing the number of tables loaded in parallel and scheduling the migration during off-peak hours will reduce CPU impact. Option B is the most balanced. Option A (increase DMS instance size) would increase source CPU usage. Option C (change to full load only) would require downtime. Option D (use Snowball) may not meet the 24-hour deadline due to shipping time.

Answer

Change the DMS task to perform only full load and skip ongoing replication

Answer

Increase the size of the DMS replication instance to speed up the migration

Answer

Use AWS Snowball to transfer the data offline and then use DMS for ongoing replication

Question 5

A company is migrating a 2 TB PostgreSQL database from on-premises to Amazon RDS for PostgreSQL. The migration must have minimal downtime and support ongoing replication. Which AWS service should be used for the migration?

Accepted Answer

AWS Database Migration Service (DMS) with change data capture. AWS Database Migration Service (DMS) with change data capture (CDC) is the correct choice because it supports ongoing replication from the source PostgreSQL database to Amazon RDS for PostgreSQL with minimal downtime. DMS performs a full load of the 2 TB database and then continuously applies changes using PostgreSQL's logical replication slots (via the pglogical extension or native WAL-based CDC), ensuring the target remains synchronized during the migration cutover.

Answer

AWS S3 Transfer Acceleration for direct database export

Answer

AWS Data Migration Service with AWS Glue

Answer

AWS Snowball Edge for offline data transfer

Question 6

A developer needs to deploy an Amazon RDS for MySQL DB instance that is accessible only from a specific EC2 instance in a VPC. Which configuration ensures this?

Accepted Answer

Place the RDS instance in the same VPC as the EC2 instance and configure a security group inbound rule referencing the EC2 security group. Placing the RDS instance in the same VPC as the EC2 instance and configuring a security group inbound rule that references the EC2 instance's security group allows traffic only from that specific EC2 instance. Security group rules are stateful and support referencing other security groups as sources, which provides a precise and secure method for controlling database access without exposing the RDS instance to the broader network.

Answer

Use an IAM role to allow the EC2 instance to connect to the RDS instance

Answer

Enable public accessibility and assign a public IP to the RDS instance

Answer

Place RDS and EC2 in different subnets and configure a network ACL

Question 7

A company is migrating a 5 TB Oracle database to Amazon Aurora PostgreSQL. The migration must be completed within a weekend. The on-premises network has a 1 Gbps connection to AWS. What is the MOST efficient migration strategy?

Accepted Answer

Use AWS DMS with direct connect to export the Oracle database directly to Aurora. With a 1 Gbps connection, the theoretical maximum transfer rate is ~450 GB/hour, so transferring 5 TB would take about 11 hours, well within a weekend. AWS DMS with Direct Connect provides a dedicated, high-bandwidth path for the migration, making it the most efficient strategy. Snowball Edge (Option D) requires ordering, loading, shipping (1-2 days), and importing, which cannot complete within a weekend. Options A and C are less efficient: S3 Transfer Acceleration adds unnecessary steps, and DMS with CDC is designed for ongoing replication, not initial load.

Answer

Use AWS S3 Transfer Acceleration to upload the database dump to S3 and then load into Aurora

Answer

Use AWS DMS with change data capture over the existing network connection

Answer

Use AWS Snowball Edge to transfer the data and then load into Aurora

Question 8

An administrator needs to migrate an on-premises MongoDB database to Amazon DocumentDB. The migration must have near-zero downtime. Which approach should the administrator use?

Accepted Answer

Use AWS DMS with MongoDB as source and DocumentDB as target. AWS DMS supports ongoing replication (change data capture) from MongoDB to Amazon DocumentDB, enabling near-zero downtime migrations by keeping the target synchronized with the source until cutover. This approach avoids the downtime required by offline methods like mongodump/mongorestore or bulk data transfer tools.

Answer

Use AWS DataSync to transfer the MongoDB data files

Answer

Use AWS Glue to extract and load data

Answer

Use mongodump to export and mongorestore to import

Question 9

A company wants to deploy a highly available Amazon RDS for MySQL database across two Availability Zones. Which feature should be enabled?

Accepted Answer

Multi-AZ deployment. Multi-AZ deployment synchronously replicates data to a standby instance in a different Availability Zone, providing automatic failover in case of an AZ outage. This is the correct feature for achieving high availability across two Availability Zones, as it ensures minimal downtime without manual intervention.

Answer

Read replicas in a different AZ

Answer

Automated backups with retention

Answer

Enhanced Monitoring

Question 10

An administrator is setting up an AWS DMS replication instance and attaches the IAM policy shown in the exhibit. The administrator receives an error that the replication instance cannot be created. Which missing permission is the MOST likely cause?

Accepted Answer

ec2:DescribeSecurityGroups. When creating a DMS replication instance, AWS DMS needs to create and manage network interfaces in the customer's VPC. The `ec2:DescribeSecurityGroups` permission is required for DMS to validate and describe the security groups specified during replication instance creation. Without this permission, the service cannot verify the security group IDs, leading to a creation failure.

Answer

ec2:DescribeVpcPeeringConnections

Answer

ec2:CreateNetworkInterfacePermission

Answer

dms:CreateReplicationInstance

Question 11

A company is migrating a 500 GB SQL Server database to Amazon RDS for SQL Server. The migration must minimize downtime and support ongoing replication. Which TWO AWS services should be used together?

Accepted Answer

AWS Database Migration Service (DMS). AWS Database Migration Service (DMS) is the correct choice because it supports ongoing replication (change data capture) from a source SQL Server database to Amazon RDS for SQL Server with minimal downtime. DMS can perform a full load followed by continuous replication of changes, allowing the source to remain operational during migration.

Answer

AWS Lambda

Answer

AWS Snowball Edge

Answer

AWS RDS SQL Server native backup and restore

Question 12

A company is deploying a new Amazon RDS for PostgreSQL DB instance. Which THREE actions are recommended for a secure deployment?

Accepted Answer

Enable encryption at rest using AWS KMS. Enabling encryption at rest using AWS KMS ensures that the underlying storage for the RDS for PostgreSQL DB instance is encrypted using AES-256 encryption. This protects data at rest against unauthorized physical access to the storage media and is a fundamental security best practice. KMS integration also allows for centralized key management and audit trails via AWS CloudTrail.

Answer

Use the default VPC for simplicity

Answer

Delete automated backups after the initial snapshot to reduce costs

Question 13

A company is migrating a 10 TB Oracle data warehouse to Amazon Redshift. The migration must minimize data transfer costs and ensure data integrity. Which TWO steps should the company take?

Accepted Answer

Use AWS Schema Conversion Tool (SCT) to convert the Oracle schema to Redshift. The AWS Schema Conversion Tool (SCT) is specifically designed to convert Oracle database schemas to Amazon Redshift-compatible schemas, handling data type mappings, stored procedures, and other schema objects. This step is critical for a successful migration as it ensures the target schema is optimized for Redshift's columnar storage and MPP architecture, reducing manual rework and potential data integrity issues.

Answer

Use AWS DMS to replicate data directly over the internet

Answer

Use Amazon Kinesis Data Streams to stream data to Redshift

Answer

Use Amazon Redshift Spectrum to query data in S3 after loading

Question 14

An administrator is deploying an Amazon RDS for MySQL DB instance and needs to ensure that all connections use SSL. Which parameter should be set on the RDS DB instance?

Accepted Answer

Set require_secure_transport=ON in the DB parameter group. Setting `require_secure_transport=ON` in the DB parameter group enforces that all connections to the RDS MySQL DB instance must use SSL/TLS. This parameter, supported by MySQL 5.7 and later, rejects any non-encrypted connection attempt, ensuring transport layer security for all client-server communication.

Answer

Set ssl_cipher in the DB parameter group

Answer

Set tls_version in the DB parameter group

Answer

Set rds.force_ssl=1 in the DB parameter group

Question 15

A company needs to deploy a globally distributed application with a database that supports multi-region writes and automatic conflict resolution. Which AWS database service should be used?

Accepted Answer

Amazon DynamoDB Global Tables. Amazon DynamoDB Global Tables is the correct choice because it provides a fully managed, multi-Region, multi-active database that replicates data across AWS Regions with automatic conflict resolution using last-writer-wins (LWW) or application-defined conflict resolution. This directly meets the requirement for multi-region writes and automatic conflict resolution without requiring custom replication logic.

Answer

Amazon Aurora Global Database

Answer

Amazon RDS for MySQL with Multi-AZ

Answer

Amazon ElastiCache for Redis