* If ``CLEARML_HOST_IP`` is not provided, then **ClearML Agent Services** uses the external public address of the **ClearML Server**.
* If ``CLEARML_AGENT_GIT_USER`` / ``CLEARML_AGENT_GIT_PASS`` are not provided, then **ClearML Agent Services** can't access any private repositories for running service tasks.
1. If upgrading from **Trains Server** version 0.15 or older, a data migration is required before continuing this upgrade. See instructions [here](clearml_server_es7_migration.md).
1. If upgrading from ClearML Server version older than 1.2, you need to migrate your data before upgrading your server. See instructions [here](clearml_server_mongo44_migration.md).