Start of the migration
Migration is the process of migrating data and configurations from a source instance to a target instance. For this purpose, a distinction is made between a recurring delta migration and a final migration. A complete migration includes both delta migrations and a final migration, each of which must be started.
Requirements
To start the migration, the Exporter must be installed and configured on the source instance,
and the Importer) must be installed and configured on the target instance.
In the minimum configuration, the API key, the SSH key, the host of the source instance to be migrated and the migration times must be configured.
Source instance
The source instance contains all the Dogus that are to be migrated to the target instance. This also means that dogus that are not to be migrated must be deleted before the migration. For example, if you want to migrate from a Jira-Dogu to a Redmine-Dogu, this migration must already take place on the source instance. The dogus ngnix, Backup & Restore, Registrator and Monitoring are an exception. These no longer exist in a Cloudogu EcoSystem on a multinode basis (CES-MN), but have their own implementations in the CES-MN. Migration to the corresponding counterpart is taken into account by the automatic migration. User intervention is not necessary.
Target instance
All Dogus that are to be migrated from the source instance are installed on the target instance. Make sure that the Dogus are installed in the same version. The automatic migration requires the Dogus to have the same version and checks this during the migration. If the versions are not identical, the migration is aborted. If additional Dogus, such as Grafana, are to be used on the CES-MN instance, these may only be installed after successful migration of the source instance.
Process
Different times are selected for the delta migration and the final migration for the process or start of the migration.
The delta migration is based on a configured schedule in the form of cron syntax, e.g. every night at 2 am (0 2 * * *).
A delta migration is started when the time is reached. The final migration is based on a fixed time in the future.
Once this is reached, the final migration starts.
A delta migration and a final migration can never run in parallel. The start of a final migration is blocked or postponed by a running delta migration. In this scenario, the final migration starts as soon as the delta migration has been completed. In contrast, delta migrations can no longer be started as soon as the time of the final migration has been reached.
In principle, a migration can also be executed without configuring a final time. In this case, delta migration would be executed continuously and only stopped by setting the final time later. This can be useful if the time of the final migration has not yet been determined, but the target instance already needs to be prepared or tested. The entire migration is only considered to be complete when the final migration is finished.
After each migration, whether delta or final migration, an e-mail is sent to the e-mail addresses that have been configured with the status and any errors.