AWS Compute Blog

Maintaining a local copy of your data in AWS Local Zones

This post is written by Leonardo Solano, Senior Hybrid Cloud SA and Obed Gutierrez, Solutions Architect, Enterprise.

This post covers data replication strategies to back up your data into AWS Local Zones. These strategies include database replication, file based and object storage replication, and partner solutions for Amazon Elastic Compute Cloud (Amazon EC2).

Customers running workloads in AWS Regions are likely to require a copy of their data in their operational location for either their backup strategy or data residency requirements. To help with these requirements, you can use Local Zones.

Local Zones is an AWS infrastructure deployment that places compute, storage, database, and other select AWS services close to large population and industry centers. With Local Zones, customers can build and deploy workloads to comply with state and local data residency requirements in sectors such as healthcare, financial services, gaming, and government.

Solution overview

This post assumes the database source is Amazon Relational Database Service (Amazon RDS). To backup an Amazon RDS database to Local Zones, there are three options:

  1. AWS Database Migration Service (AWS DMS)
  2. AWS DataSync
  3. Backup to Amazon Simple Storage Service (Amazon S3)

. Amazon RDS replication to Local Zones with AWS DMS

Figure 1. Amazon RDS replication to Local Zones with AWS DMS

To replicate data, AWS DMS needs a source and a target database. The source database should be your existing Amazon RDS database. The target database is placed in an EC2 instance in the Local Zone. A replication job is created in AWS DMS, which maintains the source and target databases in sync. The replicated database in the Local Zone can be accessed through a VPN. Your database administrator can directly connect to the database engine with your preferred tool.

With this architecture, you can maintain a locally accessible copy of your databases, allowing you to comply with regulatory requirements.

Prerequisites

The following prerequisites are required before continuing:

  • An AWS Account with Administrator permissions;
  • Installation of the latest version of AWS Command Line Interface (AWS CLI v2);
  • An Amazon RDS database.

Walkthrough

1. Enabling Local Zones

First, you must enable Local Zones. Make sure that the intended Local Zone is parented to the AWS Region where the environment is running. Edit the commands to match your parameters, group-name makes reference to your local zone group and region to the region identifier to use.

aws ec2 modify-availability-zone-group \
  --region us-east-1 \
  --group-name us-east-1-qro-1\
  --opt-in-status opted-in

If you have an error when calling the ModifyAvailabilityZoneGroup operation, you must sign up for the Local Zone.

After enabling the Local Zone, you must extend the VPC to the Local Zone by creating a subnet in the Local Zone:

aws ec2 create-subnet \
  --region us-east-1 \
  --availability-zone us-east-1-qro-1a \
  --vpc-id vpc-02a3eb6585example \
  --cidr-block my-subnet-cidr

If you need a step-by-step guide, refer to Getting started with AWS Local Zones. Enabling Local Zones is free of charge. Only deployed services in the Local Zone incur billing.

2. Set up your target database

Now that you have the Local Zone enabled with a subnet, set up your target database instance in the Local Zone subnet that you just created.

You can use AWS CLI to launch it as an EC2 instance:

aws ec2 run-instances \
  --region us-east-1 \
  --subnet-id subnet-08fc749671example \
  --instance-type t3.medium \
  --image-id ami-0abcdef123example \
  --security-group-ids sg-0b0384b66dexample \
  --key-name my-key-pair

You can verify that your EC2 instance is running with the following command:

aws ec2 describe-instances --filters "Name=availability-zone,Values=us-east-1-qro-1a" --query "Reservations[].Instances[].InstanceId"

Output:

 $ ["i-0cda255374example"]

Note that not all instance types are available in Local Zones. You can verify it with the following AWS CLI command:

aws ec2 describe-instance-type-offerings --location-type "availability-zone" \
--filters Name=location,Values=us-east-1-qro-1a --region us-east-1

Once you have your instance running in the Local Zone, you can install the database engine matching your source database. Here is an example of how to install MariaDB:

  1. Updates all packages to the latest OS versionsudo yum update -y
  2. Install MySQL server on your instance, this also creates a systemd servicesudo yum install -y mariadb-server
  3. Enable the service created in previous stepsudo systemctl enable mariadb
  4. Start the MySQL server service on your Amazon Linux instancesudo systemctl start mariadb
  5. Set root user password and improve your DB securitysudo mysql_secure_installation

You can confirm successful installation with these commands:

mysql -h localhost -u root -p
SHOW DATABASES;

3. Configure databases for replication

In order for AWS DMS to replicate ongoing changes, you must use change data capture (CDC), as well as set up your source and target database accordingly before replication:

Source database:

  • Make sure that the binary logs are available to AWS DMS:

 call mysql.rds_set_configuration('binlog retention hours', 24);

  • Set the binlog_format parameter to “ROW“.
  • Set the binlog_row_image parameter to “Full“.
  • If you are using Read replica as source, then set the log_slave_updates parameter to TRUE.

For detailed information, refer to Using a MySQL-compatible database as a source for AWS DMS, or sources for your migration if your database engine is different.

Target database:

  • Create a user for AWS DMS that has read/write privileges to the MySQL-compatible database. To create the necessary privileges, run the following commands.
CREATE USER ''@'%' IDENTIFIED BY '';
GRANT ALTER, CREATE, DROP, INDEX, INSERT, UPDATE, DELETE, SELECT ON .* TO 
''@'%';
GRANT ALL PRIVILEGES ON awsdms_control.* TO ''@'%';
  • Disable foreign keys on target tables, by adding the next command in the Extra connection attributes section of the AWS DMS console for your target endpoint.

Initstmt=SET FOREIGN_KEY_CHECKS=0;

  • Set the database parameter local_infile = 1 to enable AWS DMS to load data into the target database.

4. Set up AWS DMS

Now that you have our Local Zone enabled with the target database ready and the source database configured, you can set up AWS DMS Replication instance.

Go to AWS DMS in the AWS Management Console, and under Migrate data select Replication Instances, then select the Create Replication button:

This shows the Create replication Instance, where you should fill up the parameters required:

Note that High Availability is set to Single-AZ, as this is a test workload, while Multi-AZ is recommended for Production workloads.

Refer to the AWS DMS replication instance documentation for details about how to size your replication instance.

Important note

To allow replication, make sure that you set up the replication instance in the VPC that your environment is running, and configure security groups from and to the source and target database.

Now you can create the DMS Source and Target endpoints:

5. Set up endpoints

Source endpoint:

In the AWS DMS console, select Endpoints, select the Create endpoint button, and select Source endpoint option. Then, fill the details required:

Make sure you select your RDS instance as Source by selecting the check box as show in the preceding figure. Moreover, include access to endpoint database details, such as user and password.

You can test your endpoint connectivity before creating it, as shown in the following figure:

If your test is successful, then you can select the Create endpoint button.

Target endpoint:

In the same way as the Source in the console, select Endpoints, select the Create endpoint button, and select Target endpoint option, then enter the details required, as shown in the following figure:

In the Access to endpoint database section, select Provide access information manually option, next add your Local Zone target database connection details as shown below. Notice that Server name value, should be the IP address of your target database.

Make sure you go to the bottom of the page and configure Extra connection attributes in the Endpoint settings, as described in the Configure databases for replication section of this post:

Like the source endpoint, you can test your endpoint connection before creating it.

6. Create the replication task

Once the endpoints are ready, you can create the migration task to start the replication. Under the Migrate Data section, select Database migration tasks, hit the Create task button, and configure your task:

Select Migrate existing data and replicate ongoing changes in the Migration type parameter.

Enable Task logs under Task Settings. This is recommended as it can help you with troubleshooting purposes.

In Table mappings, include the schema you want to replicate to the Local Zone database:

Once you have defined Task Configuration, Task Settings, and Table Mappings, you can proceed to create your database migration task.

This will trigger your migration task. Now wait until the migration task completes successfully.

7. Validate replicated database

After the replication job completes the Full Load, proceed to validate at your target database. Connect to your target database and run the following commands:

USE example;
SHOW TABLES;

As a result you should see the same tables as the source database.

MySQL [example]> SHOW TABLES;
+----------------------------+
| Tables_in_example          |
+----------------------------+
| actor                      |
| address                    |
| category                   |
| city                       |
| country                    |
| customer                   |
| customer_list              |
| film                       |
| film_actor                 |
| film_category              |
| film_list                  |
| film_text                  |
| inventory                  |
| language                   |
| nicer_but_slower_film_list |
| payment                    |
| rental                     |
| sales_by_film_category     |
| sales_by_store             |
| staff                      |
| staff_list                 |
| store                      |
+----------------------------+
22 rows in set (0.06 sec)

If you get the same tables from your source database, then congratulations, you’re set! Now you can maintain and navigate a live copy of database in the Local Zone for data residency purposes.

Clean up

When you have finished this tutorial, you can delete all the resources that have been deployed. You can do this in the Console or by running the following commands in the AWS CLI:

  1. Delete target DB: 
    aws ec2 terminate-instances --instance-ids i-abcd1234
  2. Decommision AWS DMS
    • Replication Task: 
      aws dms delete-replication-task --replication-task-arn arn:aws:dms:us-east-1:111111111111:task:K55IUCGBASJS5VHZJIIEXAMPLE
    • Endpoints: 
      aws dms delete-endpoint --endpoint-arn arn:aws:dms:us-east-1:111111111111:endpoint:OUJJVXO4XZ4CYTSEG5XEXAMPLE
    • Replication instance: 
      aws dms delete-replication-instance --replication-instance-arn us-east-1:111111111111:rep:T3OM7OUB5NM2LCVZF7JEXAMPLE
  3. Delete Local Zone subnet 
    aws ec2 delete-subnet --subnet-id subnet-9example

Conclusion

Local Zones is a useful tool for running applications with low latency requirements or data residency regulations. In this post, you have learned how to use AWS DMS to seamlessly replicate your data to Local Zones. With this architecture you can efficiently maintain a local copy of your data in Local Zones and access it securly.

If you are interested on how to automate your workloads deployments in Local Zones, make sure you check this workshop.