Transferring data by creating and restoring a logical dump

1. If you do not have Terraform yet, install it.

2. Get the authentication credentials. You can add them to environment variables or specify them later in the provider configuration file.

3. Configure and initialize a provider. There is no need to create a provider configuration file manually, you can download it.

4. Place the configuration file in a separate working directory and specify the parameter values. If you did not add the authentication credentials to environment variables, specify them in the configuration file.

5. Download the data-migration-mysql-mmy.tf configuration file to the same working directory.

   This file describes:

   • Network.
   • Subnet.
   • Security group and the rule permitting access to the cluster.
   • Managed Service for MySQL® cluster with public internet access.
   • Virtual machine with public internet access (optional).

6. Specify the following in data-migration-mysql-mmy.tf:

   • Target cluster parameters:

     • target_mysql_version: MySQL® version. Must be the same or higher than in the source cluster.
     • target_sql_mode: SQL mode. It must be the same as in the source cluster.
     • target_db_name: Database name.
     • target_user and target_password: Database owner username and password.

   • Virtual machine parameters (optional):

     • vm_image_id: ID of the public image with Ubuntu without GPU, e.g., for Ubuntu 20.04 LTS.
     • vm_username and vm_public_key: Username and absolute path to the public key, for access to the VM. By default, the specified username is ignored in the Ubuntu 20.04 LTS image. A user with the ubuntu username is created instead. Use it to connect to the VM.

7. Make sure the Terraform configuration files are correct using this command:

   terraform validate
   

   Terraform will show any errors found in your configuration files.

8. Create the required infrastructure:

   1. Run this command to view the planned changes:

      terraform plan
      

      If you described the configuration correctly, the terminal will display a list of the resources to update and their parameters. This is a verification step that does not apply changes to your resources.

   2. If everything looks correct, apply the changes:

      1. Run this command:

         terraform apply
         

      2. Confirm updating the resources.

      3. Wait for the operation to complete.

   All the required resources will be created in the specified folder. You can check resource availability and their settings in the management console.

1. Switch the database to read-only mode to avoid losing data that can appear while creating the dump.

2. Create a directory for the dump files:

   mkdir db_dump
   

3. Install mydumper in the source cluster, e.g., for Ubuntu:

   sudo apt update && sudo apt install mydumper --yes
   

4. Create a database dump:

   mydumper \
       --triggers \
       --events \
       --routines \
       --outputdir=db_dump \
       --rows=10000000 \
       --threads=8 \
       --compress \
       --database=<DB_name> \
       --user=<username> \
       --ask-password \
       --host=<FQDN_or_IP_address>
   

   Where:

   • --triggers: Trigger dump.
   • --events: Event dump.
   • --routines: Stored procedure and function dump.
   • --outputdir: Dump file directory.
   • --rows: Number of rows in table fragments. The smaller the value, the more files in a dump.
   • --threads: Number of threads in use. The recommended value is equal to half the server's free cores.
   • --compress: Output file compression.
   • Where --host is the FQDN or IP address of the master host in the source cluster.

5. In the dump file, change the table engine names to InnoDB:

   sed -i -e 's/MyISAM/InnoDB/g' -e 's/MEMORY/InnoDB/g' `find /db_dump -name '*-schema.sql'`
   

6. Archive the dump:

   tar -cvzf db_dump.tar.gz ~/db_dump
   

This method is suitable if you created the dump with mydumper and are using an intermediate virtual machine to restore it.

1. Install the myloader utility to the host you are using to restore the dump, e.g., for Ubuntu:

   sudo apt update && sudo apt install mydumper --yes
   

2. Start the database restore from the dump:

   myloader \
       --host=c-<target_cluster_ID>.rw.mdb.yandexcloud.net \
       --directory=db_dump/ \
       --overwrite-tables \
       --threads=8 \
       --compress-protocol \
       --user=<username> \
       --ask-password
   

1. In the terminal window, go to the directory containing the infrastructure plan.

   Warning

   Make sure the directory has no Terraform manifests with the resources you want to keep. Terraform deletes all resources that were created using the manifests in the current directory.

2. Delete resources:

   1. Run this command:

      terraform destroy
      

   2. Confirm deleting the resources and wait for the operation to complete.

   All the resources described in the Terraform manifests will be deleted.