Which strategy would allow for a successful migration with the LEAST amount of downtime?
Deploy a new RDS for MySQL DB instance and configure it for access from the on-premises data center. Use the mysqldump utility to create an initial snapshot from the on-premises MySQL server, and copy it to an Amazon S3 bucket. Import the snapshot into the DB instance utilizing the MySQL utilities running on an Amazon EC2 instance. Immediately point the application to the DB instance.
Deploy a new Amazon EC2 instance, install the MySQL software on the EC2 instance, and configure networking for access from the on-premises data center. Use the mysqldump utility to create a snapshot of the on-premises MySQL server. Copy the snapshot into the EC2 instance and restore it into the EC2 MySQL instance. Use AWS DMS to migrate data into a new RDS for MySQL DB instance. Point the application to the DB instance.
Deploy a new Amazon EC2 instance, install the MySQL software on the EC2 instance, and configure networking for access from the on-premises data center. Use the mysqldump utility to create a snapshot of the on-premises MySQL server. Copy the snapshot into an Amazon S3 bucket and import the snapshot into a new RDS for MySQL DB instance using the MySQL utilities running on an EC2 instance. Point the application to the DB instance.
Deploy a new RDS for MySQL DB instance and configure it for access from the on-premises data center. Use the mysqldump utility to create an initial snapshot from the on-premises MySQL server, and copy it to an Amazon S3 bucket. Import the snapshot into the DB instance using the MySQL utilities running on an Amazon EC2 instance. Establish replication into the new DB instance using MySQL replication. Stop application access to the on-premises MySQL server and let the remaining transactions replicate over. Point the application to the DB instance.
Explanations:
Usingmysqldumpwith large datasets like 4 TB can be slow and result in significant downtime. The process does not allow for efficient continuous synchronization between the on-premises database and the new RDS instance, which is essential to minimize downtime during migration.
The process of migrating using an EC2 instance withmysqldumpand AWS DMS involves too many steps and does not provide a streamlined approach for reducing downtime. Additionally, usingmysqldumpon a large database can be slow and result in excessive downtime.
While using S3 to store the snapshot is a good practice, the use ofmysqldumpon large databases can cause considerable downtime. This option also lacks an efficient mechanism to keep the source and destination databases in sync during the migration.
This strategy involves using MySQL replication to synchronize the on-premises database and the new RDS instance after the initial snapshot, which minimizes downtime by allowing for ongoing replication of changes. Once the replication catches up, the application can be switched over with minimal interruption. This is the most efficient method to migrate with the least downtime.