Migrate to Aiven for MySQL from an external MySQL#

Aiven for MySQL offers a managed process for migrating from an external MySQL into the Aiven-hosted database. It supports both a one-off dump-and-restore process and using the ongoing replication functionality built-in to MySQL. The process will first do a mysqldump to seed the schema and bulk-copy the data; if the preconditions are met for ongoing replication then it will configure MySQL as a replica of the external database.

Requirements#

To perform a migration from an external MySQL to Aiven for MySQL the following requirements need to be satisfied:

The source server needs to be publicly available or accessible via a virtual private cloud (VPC) peering connection between the private networks, and any firewalls need to be open to allow traffic between the source and target servers.
You have a user account on the source server with sufficient privileges to create a user for the replication process.
GTID is enabled on the source database. To review the current GTID setting, run the following command on the source cluster:

show global variables like 'gtid_mode';

Note

If you are migrating from MySQL in GCP, you need to enable backups with PITR for GTID to be set to on

Variables#

You can use the following variables in the code samples provided:

Variable	Description
`SRC_HOSTNAME`	Hostname for source MySQL connection
`SRC_PORT`	Port for source MySQL connection
`SRC_USERNAME`	Username for source MySQL connection
`SRC_PASSWORD`	Password for source MySQL connection
`SRC_IGNORE_DBS`	Comma-separated list of databases to ignore in migration
`SRC_SSL`	SSL setting for source MySQL connection
`DEST_NAME`	Name of the destination Aiven for MySQL service
`DEST_PLAN`	Aiven plan for the destination Aiven for MySQL service (e.g. `startup-4`, `business-32`, etc)

Perform the migration#

Create a user in the source database with sufficient privileges for the pre-flight checks, the mysqldump, and the ongoing replication (you can substitute % in the below command with the IP address of the Aiven for MySQL database, if already existing):
```
create user 'SRC_USERNAME'@'%' identified by 'SRC_PASSWORD';
grant replication slave on *.* TO 'SRC_USERNAME'@'%';
grant select, process, event on *.* to 'SRC_USERNAME'@'%'
```
If you don’t have an Aiven for MySQL database yet, create it via Aiven Console or the dedicated Aiven CLI command

Set the migration details via the avn service update Aiven CLI command substituting the parameters accordingly:

avn service update --project PROJECT_NAME \
    -c migration.host=SRC_HOSTNAME \
    -c migration.port=SRC_PORT \
    -c migration.username=SRC_USERNAME \
    -c migration.password=SRC_PASSWORD \
    -c migration.ignore_dbs=SRC_IGNORE_DBS \
    -c migration.ssl=SRC_SSL \
    DEST_NAME

Check the migration status via the dedicated avn service migration-status Aiven CLI command:
```
avn --show-http service migration-status --project PROJECT_NAME DEST_NAME
```

Whilst the migration process is ongoing, the migration_detail.status will be syncing:

{
  "migration": {
      "error": null,
      "method": "replication",
      "seconds_behind_master": 0,
      "source_active": true,
      "status": "done"
  },
  "migration_detail": [
      {
          "dbname": "migration",
          "error": null,
          "method": "replication",
          "status": "syncing"
      }
  ]
}

Note

The migration will initially do a bulk-copy of your data, and then several minutes after that has finished it will use the built-in replication feature of MySQL to commence ongoing data copying. You can see MySQL’s internal status by running show replica status on the destination database.

Stop the replication#

If you reach a point where you no longer need the ongoing replication to happen, you can remove the configuration from the destination service via the avn service update Aiven CLI command:

avn service update --project PROJECT_NAME --remove-option migration DEST_NAME