[Yandex Cloud documentation](../../../index.md) > [Yandex Managed Service for MySQL®](../../index.md) > [Tutorials](../index.md) > [Migrating a database from a third-party MySQL® cluster](index.md) > Migrating data using a logical dump
# Transferring data from a third-party MySQL® cluster by creating and restoring a logical dump
# Transferring data by creating and restoring a logical dump
To move data to a Managed Service for MySQL® cluster, create a logical dump of the desired database and restore it to the target cluster. There are two ways to do this:
* Use the `mydumper` and `myloader` [utilities](https://github.com/mydumper/mydumper). A database dump is created as a collection of files in a separate folder.
* Use `mysqldump` and `mysql`. A database dump is created as a single file.
Migration stages:
1. [Create a dump](#dump) of the database you want to migrate.
1. Optionally, [upload a dump to an intermediate virtual machine](#vm-load) in Yandex Cloud.
You need to transfer your data to the staging Yandex Compute Cloud VM in one of the following situations:
* Your Managed Service for MySQL® cluster is not reachable from the internet.
* Your hardware or connection to the cluster in Yandex Cloud is not very reliable.
The larger the amount of data to be migrated and the required migration speed, the higher the virtual machine requirements: number of processor cores, RAM, and disk space.
1. [Restore data from the dump](#restore).
If you no longer need the resources you created, [delete them](#clear-out).
## Required paid resources {#paid-resources-logical-dump}
* Managed Service for MySQL® cluster, which includes computing resources allocated to hosts, storage and backup size (see [Managed Service for MySQL® pricing](../../pricing.md)).
* Public IP addresses if public access is enabled for cluster hosts (see [Virtual Private Cloud pricing](../../../vpc/pricing.md)).
* Virtual machine if created to upload a dump: use of computing resources, storage, public IP address, and OS (see [Compute Cloud pricing](../../../compute/pricing.md)).
## Getting started {#before-you-begin}
Create the required resources:
{% list tabs group=instructions %}
- Manually {#manual}
1. Create a [target Managed Service for MySQL® cluster](../../operations/cluster-create.md) with your preferred configuration. In this case, the following applies:
* The MySQL® version must be the same or higher than the version in the source cluster.
Data transfer with a major MySQL® version upgrade is possible but not guaranteed. For more information, see [this MySQL® article](https://dev.mysql.com/doc/refman/8.0/en/faqs-migration.html).
Migration to an earlier MySQL® version is [not supported](https://dev.mysql.com/doc/refman/8.0/en/downgrading.html).
* [SQL mode](../../concepts/settings-list.md#setting-sql-mode) must be the same as in the source cluster.
1. Optionally, [create a VM](../../../compute/operations/vm-create/create-linux-vm.md) based on [Ubuntu 20.04 LTS](https://yandex.cloud/en/marketplace/products/yc/ubuntu-20-04-lts) with the following parameters:
* **Disks and file storages** → **Size**: Sufficient to store both archived and unarchived dumps.
The recommended size is two or three times the total dump and dump archive size.
* **Network settings**:
* **Subnet**: Choose a subnet within the target cluster’s cloud network.
* **Public IP address**: Select either `Auto` or a reserverd IP address from the list.
1. If you use security groups for the staging VM and the Managed Service for MySQL® cluster, [configure them](../../operations/connect/index.md#configure-security-groups).
- Terraform {#tf}
1. If you do not have Terraform yet, [install it](../../../tutorials/infrastructure-management/terraform-quickstart.md#install-terraform).
1. [Get the authentication credentials](../../../tutorials/infrastructure-management/terraform-quickstart.md#get-credentials). You can add them to environment variables or specify them later in the provider configuration file.
1. [Configure and initialize a provider](../../../tutorials/infrastructure-management/terraform-quickstart.md#configure-provider). There is no need to create a provider configuration file manually, you can [download it](https://github.com/yandex-cloud-examples/yc-terraform-provider-settings/blob/main/provider.tf).
1. Place the configuration file in a separate working directory and [specify the parameter values](../../../tutorials/infrastructure-management/terraform-quickstart.md#configure-provider). If you did not add the authentication credentials to environment variables, specify them in the configuration file.
1. Download the [data-migration-mysql-mmy.tf](https://github.com/yandex-cloud-examples/yc-mysql-data-migration-from-on-premise/blob/main/data-migration-mysql-mmy.tf) configuration file to the same working directory.
This file describes:
* [Network](../../../vpc/concepts/network.md#network).
* [Subnet](../../../vpc/concepts/network.md#subnet).
* [Security group](../../../vpc/concepts/security-groups.md) and the rule allowing inbound cluster connections.
* Managed Service for MySQL® cluster with public internet access.
* Virtual machine with public internet access (optional).
1. In `data-migration-mysql-mmy.tf`, specify the following:
* Target cluster settings:
* `target_mysql_version`: MySQL® version. This version must be the same or higher than the version in the source cluster.
* `target_sql_mode`: [SQL mode](../../concepts/settings-list.md#setting-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`: Public Ubuntu [image](../../../compute/operations/images-with-pre-installed-software/get-list.md) ID (non-GPU), e.g., [Ubuntu 20.04 LTS](https://yandex.cloud/en/marketplace/products/yc/ubuntu-20-04-lts).
* `vm_username` and `vm_public_key`: Username and absolute path to the [public key](../../../compute/operations/vm-connect/ssh.md#creating-ssh-keys) to use for access to the virtual machine. By default, the [Ubuntu 20.04 LTS](https://yandex.cloud/en/marketplace/products/yc/ubuntu-20-04-lts) image ignores the specified username, instead creating a user named `ubuntu`. Use it to connect to the VM.
1. Validate your Terraform configuration files using this command:
```bash
terraform validate
```
Terraform will display any configuration errors detected in your files.
1. Create the required infrastructure:
1. Run this command to view the planned changes:
```bash
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.
1. If everything looks correct, apply the changes:
1. Run this command:
```bash
terraform apply
```
1. Confirm updating the resources.
1. 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](https://console.yandex.cloud).
{% endlist %}
## Creating a dump {#dump}
{% list tabs %}
* Using the mysqldump utility
1. Switch the database to read-only
mode to avoid losing data that can appear while creating the dump.
1. Install `mysqldump` in the source cluster, e.g., for Ubuntu:
```bash
sudo apt update && sudo apt install mysql-client --yes
```
1. Create a database dump:
```bash
mysqldump \
--host= \
--user= \
--password \
--port= \
--set-gtid-purged=OFF \
--quick \
--single-transaction \
> ~/db_dump.sql
```
Where `--host` is the FQDN or IP address of the master host in the source cluster.
If required, provide additional parameters in the create dump command:
* `--events`, if there are recurring events in your database.
* `--routines`, if your database stores procedures and functions.
For InnoDB tables, use the `--single-transaction` option for data integrity.
1. In the dump file, change the table engine names to `InnoDB`:
```bash
sed -i -e 's/MyISAM/InnoDB/g' -e 's/MEMORY/InnoDB/g' db_dump.sql
```
1. Archive the dump:
```bash
tar -cvzf db_dump.tar.gz ~/db_dump.sql
```
* Using the mydumper utility
1. Switch the database to read-only
mode to avoid losing data that can appear while creating the dump.
1. Create a directory for the dump files:
```bash
mkdir db_dump
```
1. Install `mydumper` in the source cluster, e.g., for Ubuntu:
```bash
sudo apt update && sudo apt install mydumper --yes
```
1. Create a database dump:
```bash
mydumper \
--triggers \
--events \
--routines \
--outputdir=db_dump \
--rows=10000000 \
--threads=8 \
--compress \
--database= \
--user= \
--ask-password \
--host=
```
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.
1. In the dump file, change the table engine names to `InnoDB`:
```bash
sed -i -e 's/MyISAM/InnoDB/g' -e 's/MEMORY/InnoDB/g' `find /db_dump -name '*-schema.sql'`
```
1. Archive the dump:
```bash
tar -cvzf db_dump.tar.gz ~/db_dump
```
{% endlist %}
## Uploading a dump to a virtual machine in Yandex Cloud (optional) {#vm-load}
1. [Connect](../../../compute/operations/vm-connect/ssh.md) to an intermediate virtual machine over SSH.
1. Copy the archive containing the database dump to the intermediate virtual machine, e.g., using `scp`:
```bash
scp ~/db_dump.tar.gz @:~/db_dump.tar.gz
```
1. Extract the dump from the archive:
```bash
tar -xzf ~/db_dump.tar.gz
```
## Restoring data {#restore}
{% note alert %}
For Managed Service for MySQL® clusters, [AUTOCOMMIT](https://dev.mysql.com/doc/refman/8.0/en/server-system-variables.html#sysvar_autocommit) is enabled by default. **Do not disable** AUTOCOMMIT during the client session when restoring the database from the dump, otherwise the host storage may overflow and the cluster may not function properly.
{% endnote %}
{% list tabs %}
* Using the mysql utility
This method is suitable if you used `mysqldump` to create the dump.
1. Install the `mysql` utility to the host you are using to restore the dump, e.g., for Ubuntu:
```bash
sudo apt update && sudo apt install mysql-client --yes
```
1. Start the database restore from the dump:
* If you are restoring a dump from a VM located in Yandex Cloud:
```bash
mysql \
--host=c-.rw.mdb.yandexcloud.net \
--user= \
--port=3306 \
< ~/db_dump.sql
```
* If you are restoring the dump from a host connecting to Yandex Cloud from the internet, [get an SSL certificate](../../operations/connect/index.md#get-ssl-cert) and provide the `--ssl-ca` and the `--ssl-mode` parameters in the restore command:
```bash
mysql \
--host=c-.rw.mdb.yandexcloud.net \
--user= \
--port=3306 \
--ssl-ca=~/.mysql/root.crt \
--ssl-mode=VERIFY_IDENTITY \
< ~/db_dump.sql
```
* Using the myloader utility
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:
```bash
sudo apt update && sudo apt install mydumper --yes
```
1. Start the database restore from the dump:
```bash
myloader \
--host=c-.rw.mdb.yandexcloud.net \
--directory=db_dump/ \
--overwrite-tables \
--threads=8 \
--compress-protocol \
--user= \
--ask-password
```
{% endlist %}
You can get the cluster ID with the [list of clusters in the folder](../../operations/cluster-list.md#list-clusters).
## Deleting the resources you created {#clear-out}
Delete the resources you no longer need to avoid paying for them:
{% list tabs group=instructions %}
- Manually {#manual}
* [Delete the Managed Service for MySQL® cluster](../../operations/cluster-delete.md).
* If you created a staging virtual machine, [delete it](../../../compute/operations/vm-control/vm-delete.md).
* If you reserved public static IP addresses, release and [delete them](../../../vpc/operations/address-delete.md).
- Terraform {#tf}
1. In the terminal window, go to the directory containing the infrastructure plan.
{% note 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.
{% endnote %}
1. Delete resources:
1. Run this command:
```bash
terraform destroy
```
1. Confirm deleting the resources and wait for the operation to complete.
All the resources described in the Terraform manifests will be deleted.
{% endlist %}