CoordinatorService stopped frequently. And rest of the services like Simulator, Portal and workstation services are also not responding properly.
CPU: 4 core CPU (Which is very minimal for server setup).
We noticed this issue in multiple scenarios. one of the scenario we observed is, there are multiple instances of Devtest components which are initiated through services (Ex. CoordinatorService, SimulatorService, etc) and through direct command prompt running in back end (Ex. Coordinator, Simulator). When all these processes are running in back end and if there is no enough CPU/Memory exists on the server, previous running services does not respond and also when you try to start the components again, it will go down.
To resolve this scenario, kill all the java processes which are related to Devtest components and start each component one by one and wait for each process until to come up.