NEW - You can now accelerate your migration and modernization with AWS Transform. Read Getting Started in the AWS Transform User Guide.

Replication server settings reference

Replication servers are lightweight Amazon EC2 instances that are used to replicate data between your source servers and AWS. Replication servers are automatically launched and terminated as needed. You can modify the behavior of the replication servers by modifying the settings for a single source server or multiple source servers. Alternatively, you can run AWS Transform MGN with the default replication server settings.

The replication server options, include:

Staging area subnet

Choose the Staging area subnet that you want to allocate as the staging area subnet for all of your replication servers. If you chose to use IPv6, you must choose a subnet that uses IPv6 CIDRs.

The best practice is to create a single dedicated, separate subnet for all of your migration waves using your AWS account. Learn more about creating subnets in this AWS VPC article.

If a default subnet does not exist, select a specific subnet. The drop-down menu contains a list of all subnets that are available in the console's AWS Region.

Using multiple subnets

The best practice is to use a single staging area subnet for all of your migration waves within a single AWS account. You may want to use multiple subnets in certain cases, such as the migration of thousands of servers.

Launching replication servers in Availability Zones

If you want your replication servers to be launched in a specific Availability Zone, then select or create a subnet in that specific Availability Zone. Learn more about using Availability Zones in this Amazon Elastic Compute Cloud article.

Replication server instance type

Choose the Replication server instance type. This determines the instance type and size that is used for the launch of each replication server.

The best practice is to not change the default replication server instance type unless there is a business need for doing so. By default, AWS Transform MGN uses the t3.small instance type. This is the most cost effective instance type and should work well for most common workloads. You can change the replication server instance type to speed up the initial sync of data from your source servers to AWS. Changing the instance type will likely lead to increased compute costs.

You can choose a the Replication server instance type from the drop-down menu contains all available types. Recommended and commonly used instance types are displayed first. You can also search for a specific instance type in the search box.

You can change the replication server instance type for servers that are replicating too slowly or servers that are constantly busy or experience frequent spikes. These are the most common instance type changes:

Dedicated instance for replication server

Choose whether you would like to use a Dedicated instance for replication server.

When an external server is very write-intensive, the replication of data from its disks to a shared Replication Server can interfere with the data replication of other servers. In these cases you should choose the Use dedicated replication server option (and also consider changing Replication server instance type).

Otherwise, choose the Do not use dedicated replication server option.

Target storage type

AWS Transform MGN supports two target storage types for replication. You can select the storage type that best suits your workload requirements:

Store snapshots in AWS Local Zone

When you replicate to a Local Zone, you can store Amazon EBS snapshots in the Local Zone instead of the parent AWS Region.

By default, snapshots of Amazon EBS volumes in a Local Zone are stored in the parent AWS Region. If you replicate to a Local Zone that supports local snapshots, you can store the snapshots locally in the Local Zone to meet data residency requirements.

This setting is available only when the staging area subnet is in a supported Local Zone.

For more information about local snapshots in Local Zones, see Local snapshots in Local Zones in the Amazon EBS User Guide.

Always use Application Migration Service security group

Choose whether you would like to Always use the Application Migration Service security group.

A security group acts as a virtual firewall, which controls the inbound and outbound traffic of the staging area subnet.

The best practice is to have AWS Transform MGN automatically attach and monitor the default Application Migration Service Security Group. This group opens inbound TCP Port 1500 for receiving the transferred replicated data. When the default Application Migration Service Security Group is activated, MGN will constantly monitor whether the rules within this security group are enforced, in order to maintain uninterrupted data replication. If these rules are altered, MGN will automatically fix the issue.

Select the Always use Application Migration Service security group option to allow data to flow from your source servers to the replication servers, and that the replication servers can communicate their state to the AWS Transform MGN servers.

Otherwise, select the Do not use Application Migration Service security group option. Selecting this option is not recommended.

Additional security groups can be chosen from the Additional security groups dropdown. The list of available security groups changes according to the Staging area subnet you selected.

You can search for a specific security group within the search box.

You can add security groups via the AWS Management Console, and they will appear on the security group drop-down list in the AWS Transform MGN Console. Learn more about AWS security groups in this VPC article.

You can use the default Application Migration Service security group, or you can select another security group. However, take into consideration that any selected security group that is not the Application Migration Service default, will be added to the default group, since the default security group is essential for the operation of MGN.

Data routing and throttling

AWS Transform MGN allows you to control how data is routed from your source servers to the replication servers on AWS through the Data routing and throttling settings.

By default, data is sent from the source servers to the replication servers over the public internet, using the public IP that was automatically assigned to the replication servers. Transferred data is always encrypted in transit.

Use private IP for data replication

Choose the Use private IP option if you want to route the replicated data from your source servers to the staging area subnet through a private network with a VPN, AWS Direct Connect, VPC peering, or another type of existing private connection.

Choose Do not use private IP if you do not want to route the replicated data through a private network.

You should use this option if you want to:

Network architecture diagram – private IP

The following diagram illustrates the high-level interaction between the different replication system components when using private IP or VPC endpoint.

Create public IP

When the Use private IP option is chosen, you will have the option to create a public IP. Public IPs are used by default. Choose Create public IP if you want to create a public IP. Choose Do not create a public IP if you do not want to create a public IP.

Throttle bandwidth

You can control the amount of network bandwidth used for data replication per server. By default, AWS Transform MGN will use all available network bandwidth utilizing five concurrent connections.

Choose Throttle bandwidth if you want to control the transfer rate of data sent from your source servers to the Replication Servers over TCP Port 1500. Otherwise, choose Do not throttle bandwidth.

If you chose to throttle bandwidth, the Throttle network bandwidth (per server, in Mbps) box will appear. Enter your desired bandwidth in Mbps.

Replication resources tags

Add custom Replication resources tags to resources created by AWS Transform MGN in your AWS account.

These are resources required to facilitate data replication, testing and cutover. Each tag consists of a key and an optional value. You can add a custom tag to all of the AWS resources that are created on your AWS account during the normal operation of AWS Transform MGN.

To add a new tag, take the following steps:

These resources include:

Learn more about AWS Tags in this Amazon EC2 article.