Hi Openstack experts, in an openstack private cloud where there are multiple controller and compute nodes, if there are problems with some service(s), how do you know which controller/compute to look for the error messages? e.g. if the neutron is not working, how do you know which controller/compute node to look for the error message for the neutron log file? Sorry I know this is a general question but want to get some sort of guidelines on what people do to troubleshoot. Many thanks!