In Denodo Scheduler, you could login or manually execute jobs and perform all the scheduler operations only when the Scheduler server is active. If the server goes down then automatically all the opened sessions will become inactive.
If you are a valid support user, you could open a support ticket in the [Denodo Support Site](https://support.denodo.com), so that our Support Team can help you.
You could refer the [Server Connectivity Details](https://community.denodo.com/docs/html/browse/6.0/scheduler/administration/administration/server_configuration/server_configuration_sections#server-connectivity-details) for more details on Scheduler server.
Hope this helps you!