For some reason if there is a requirement to change the port for Scheduler service from the default 9090 port, it can be done by updating the port in Config files. This article covers steps to be followed to change the port.
Environment
3.x
Resolution
Stop connectall-broker
Stop connectall-core
Stop connectall-scheduler
Navigate to ../Core/conf and modify ConnectAll.properties file and change the property scheduler.service.port=http://0.0.0.0:9090 to update the port number.
Navigate to ../Scheduler/conf and modify application.properties file and change the property server.port=9090 to update the port number. Make sure the ports are same in both the files.
Start connectall-broker
Start connectall-core
Start connectall-scheduler
Now login to UI and verify that Automation Schedules table on Dashboard screen does not show any error and you can trigger automation.