The scheduler service is a windows service that has no database, the only way of communication with the web sites there all the jobs is running is by remote objects for all sites listed in the EPiServer.SchedulerService.Sites.xml file (located in %ProgramFiles(x86)%\EPiServer\Shared\Services\Scheduler Service)
Disable scheduler service
It is pretty common to let the scheduled jobs only runs on the CMS machine, to disable this on the web front ends change the sites configuration in episerver.config
<sites>
<site ...
<siteSettings enableScheduler="false"
This will remove the registration of this server from the EPiServer.SchedulerService.Sites.xml located in %ProgramFiles(x86)%\EPiServer\Shared\Services\Scheduler Service.