Multiple Replication Servers in AWS DRS

This is a known issue with AWS Disaster Recovery Service (DRS) that can occur under certain conditions. To address the problem of multiple replication servers being created for a single source machine when it restarts, you can try the following steps:

1. Verify the issue: First, confirm that you're indeed seeing multiple active replication servers for a single source server in the AWS DRS console.
2. Stop replication: For the affected source server, stop the replication process temporarily from the AWS DRS console.
3. Terminate extra replication servers: Manually terminate the extra replication servers, keeping only the most recent one. You can do this from the EC2 console or using AWS CLI.
4. Update DRS settings: In the AWS DRS console, go to the settings for the affected source server and ensure that the "Replication Server instance type" is set appropriately. Sometimes, changing this setting and then changing it back can help reset the replication process.
5. Restart replication: Start the replication process again for the source server.
6. Monitor and verify: Closely monitor the replication process to ensure that only one replication server is created and maintained.
7. Contact AWS Support: If the issue persists, it's recommended to open a support ticket with AWS. They may have additional insights or potential fixes for this specific problem.
8. Consider automation: To prevent this issue from recurring, you could create an AWS Lambda function that periodically checks for and terminates extra replication servers. This would be a temporary solution while waiting for a permanent fix from AWS.
9. Keep your AWS DRS updated: Ensure you're running the latest version of AWS DRS components, as AWS may have released patches to address this issue.

I detect an anomaly. I have 13 source disks (on 7 source servers). The two Replication Server instances add up to 16 staging disks plus the boot disks. Why are 16 staging disks for 13 source replicated disks ?