def instance_update_db(context, instance_uuid, extra_values=None):
 now = timeutils.utcnow()
 values = {'host': None, 'node': None, 'scheduled_at': now}
 if extra_values:
  values.update(extra_values)
 return db.instance_update(context, instance_uuid, values)

def instance_update_db ( context , instance_uuid , extra_values = None ) : now = timeutils . utcnow ( ) values = { 'host' : None , 'node' : None , 'scheduled_at' : now } if extra_values : values . update ( extra_values ) return db . instance_update ( context , instance_uuid , values )
clear the host and node - set the scheduled_at field of an instance .