This blog introduces the AWS database migration service, a cloud-based tool, used extensively for migrating databases to the cloud.

INTRODUCTION

DMS can be used to migrate the legacy database to the cloud. However, its usage is not only limited to migration, but also provides other features like replicating databases across the regions and archiving data to S3

MIGRAION SCENARIOS

There are a couple of migration scenarios that are generally used:

On-premises to AWS cloud.

Relational database to non-relational database.

DBs hosted on EC2 to managed AWS services.

MIGRATION TOOLS

When migrating the database as per the scenario, DMS is not alone which is being used. As the DMS tool is widely used to support both homogeneous and heterogeneous migrations, other migration tools can be used as a combination to fulfill the migration requirements.

The following tools can be used as per the requirements:

AWS DMS (Database migration service)

Schema conversion tool (SCT)

Migration playbooks (best practices & migration templates)

Type of migration and tools

HOMOGENEOUS MIGRATION

If homogeneous (source and destination databases are the same) migration is planned, only DMS service can be used to migrate the database. However, still DMS does move the basic schema which is essential to move the data.

HETEROGENEOUS MIGRATION

It is a must to first convert the schema in case of heterogeneous migration. The SCT tool will first create the target database and then process and analyze the source database schema. Then it will start the conversion with some actions requiring manual intervention as well.

The benefit of SCT tool is to make the migration easy by analysis and recommendations, it also making the migration compatible with other databases i.e. MySQL, SQL Server, Oracle, PostgreSQL.

When the schema is ready after resolving the conflicts, DMS can be used to migrate the data into a target database.

Selection rules can be defined as below, at least one rule is required

DB Migration task is now ready to execute, just click on Action->Restart/Resume to start it manually.

CONCLUSION

DMS is a crucial service when planning to migrate databases to the AWS cloud. Good thing is that DMS supports almost every database as a source and target, so it is easy to move our business to the cloud. We must learn more about the other tools which can be used in combination with DMS service.

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Nashet Ali

Cloudify with Nashet.