# openstack nova can not locate which compute of one instance located on from conductor.log

when boot one instance, after successfully scheduled but failed during vm boot on one compute node, related compute node info will be clean latter. related commit is:

Change-Id: I4d9c90b1d3fcce5237323fffcc6db1fb93d23e37 Closes-Bug: #1427944

def _nil_out_instance_obj_host_and_node(self, instance):
# NOTE(jwcroppe): We don't do instance.save() here for performance
# reasons; a call to this is expected to be immediately followed by
# another call that does instance.save(), thus avoiding two writes
# to the database layer.
instance.host = None
instance.node = None


for example, when network have no more ip, instance can be scheduled but can't boot up then it will be ERROR. use 'openstack server show' CMD can not find which compute node this instance scheduled, also in log we can find nothing seems.

but sometimes, especially debug VM boot error issue, it is necessary to know which compute this instance scheduled, then we can find more info about that issue.

def build_instances(self, context, instances, image, filter_properties,