Database Migration to AWS With No Downtime

Database Migration to AWS With No Downtime

The goal of any migration is to minimize downtime. With the help of Amazon Web Services (AWS), we can virtually eliminate downtime in database migrations.

The tool we are using to perform database migrations is called AWS Database Migration Service (DMS); it helps us migrate clients' databases to AWS quickly and securely.

The production database stays fully operational trough the migration process; this feature helps us eliminate downtime. AWS DMS supports data migration to and from the most widely used commercial and open-source databases, it also supports homogeneous migrations (Oracle to Oracle) and heterogeneous migrations (Oracle or Microsoft SQL Server to Amazon Aurora).

Benefits

Simplicity and cost

AWS DMS helps us manage all the complexities of the migration process, including the replication of data changes that occurred during the migration process. The simplicity of DMS helps us minimize migration costs compared to costly traditional migration methods.

Virtually no downtime

During the migration process, the production database stays fully operational. All data changes to the production database are continually replicated to the target. After the migration procedure is successfully completed, we can keep this continuous replication; this enables us to switch databases in the most appropriate time.

Support for widely used databases

AWS Database Migration Service is very versatile; it enables us to easily migrate data to and from most of the widely used open-source and commercial databases. Homogeneous (Oracle to Oracle) and heterogeneous (migrations between different database platforms such as Oracle to Amazon Aurora) migrations are both supported. We can migrate on-premises databases to Amazon RDS or Amazon EC2, as well as one RDS database to another RDS database or even from SQL to NoSQL.

Reliability

The AWS Database Migration Service is a purpose build tool that constantly monitors all sorts of parameters such as source and target databases, network connectivity, and the replication instance. In the case of interruption, it automatically restarts the process and continues the migration process from the previous point. Once the tool has been prepared, we can even create a test run before performing the actual migration procedure.

Use cases

Homogeneous Database Migrations

In homogeneous database migrations, the source and target databases are either the same or compatible. The example of homogeneous migration is a migration from Oracle to Amazon RDS for Oracle, MySQL to Amazon Aurora, MySQL to Amazon RDS for MySQL, or Microsoft SQL Server to Amazon RDS for SQL Server. Homogeneous migration is a simple and straightforward process because schema structure, data types, and database code between source and target databases are compatible.

Heterogeneous Database Migrations

In heterogeneous database migrations, the source and target database engines are different. The example of heterogeneous migration is a migration from Oracle to Amazon Aurora, Oracle to PostgreSQL, or Microsoft SQL Server to MySQL. Heterogeneous migration is a bit more complicated; it is a two-step process. Firstly, we need to convert schema and code to match the target database by using AWS Schema Conversion Tool. Secondly, we use DMS to migrate data from source to target database.

Development and Test

AWS Database Migration Services is used to migrate data between on-premises and cloud environments; there are two situations when this is useful for development and testing. The first situation is when we have a production system on-premise while we keep development, test, or staging systems on AWS. Data is copied from on-premise systems to AWS allowing developers and testers to use copies of real production data. The second situation is when we have a production system on AWS, while development and testing is done on-premise. Data is migrated from AWS to on-premise systems either once or continuously.

Database consolidation

Another good use case for AWS Database Migration Services is database consolidation. Database consolidation is a process in which we consolidate multiple databases into a single target database. The feature can be used for all supported database engines, both for homogeneous and heterogeneous migrations. There are many possibilities for implementation. The source databases can be located on-premise, or in Amazon EC2 instances, or it can be Amazon RDS. The target database is a database in Amazon EC2 or Amazon RDS.

Continuous Data Replication

AWS Database Migration Service can be used to perform continuous data replication; this is useful for Disaster Recovery instance synchronization, geographic database distribution, and Dev/Test environment synchronization. Data can be replicated both homogeneous and heterogeneous.

Conclusion

AWS is the largest hyper cloud provider with a share of 60% of the global cloud market. The company is very customer-oriented and understands the pain points of various IT systems. That's why they build tools, services, and solutions that help us easily solve problems that were previously very hard and complicated.

Sedmi odjel, as an AWS partner and solution provider, guarantees the highest quality IT services based on AWS. Through the AWS partner program and the constant development of our relationship with AWS, we ensure that you have the best AWS experts and all the support you need to build stable, reliable, and scalable IT systems.

If you want to know more about cloud migration, cloud technology in general, AWS cloud, or you want to try AWS services:

• visit our cloud migration service page;
• give us a call at +385 1 3141 562;
• contact our sales department at sales@heptabit.com.

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