Post Migration steps after migrating MongoDB to AWS

Here are the key post-migration checks to perform after migrating a standalone MongoDB instance from on-premises to Amazon EC2 using the AWS Migration Service (MGN):

Verify the instance status:
    Check the status of the migrated EC2 instance in the Amazon EC2 console. Ensure the instance is in a "running" state and has passed the "2/2 checks" indicating the instance is healthy from an infrastructure perspective.
    If any instances fail the status checks, contact AWS Support for assistance.

Validate the MongoDB instance:
    Connect to the migrated MongoDB instance on EC2 and ensure the database is accessible and functioning correctly.
    Verify that all databases, collections, and data have been successfully migrated.
    Check the MongoDB logs for any errors or issues.

Test application connectivity:
    Ensure your application can successfully connect to the migrated MongoDB instance on EC2.
    Test key application functionality to validate the migration was successful.

Perform data validation:
    Compare the data in the on-premises MongoDB instance with the data in the migrated EC2 instance to ensure all data was transferred correctly.
    Perform sample queries and spot checks to validate the data integrity.

Update DNS and routing:
    If necessary, update your application's connection strings or DNS settings to point to the new MongoDB instance on EC2.
    Ensure your application can seamlessly connect to the migrated MongoDB instance.

Monitor the migrated instance:
    Set up appropriate monitoring and alerting for the MongoDB instance on EC2 to ensure its ongoing health and performance.
    Review CloudWatch metrics and logs to identify any issues or anomalies.