Coverage for nova/scheduler/weights/affinity.py: 88%

1# Copyright (c) 2015 Ericsson AB 

2# All Rights Reserved. 

3# 

4# Licensed under the Apache License, Version 2.0 (the "License"); you may 

5# not use this file except in compliance with the License. You may obtain 

6# a copy of the License at 

7# 

8# http://www.apache.org/licenses/LICENSE-2.0 

9# 

10# Unless required by applicable law or agreed to in writing, software 

11# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 

12# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 

13# License for the specific language governing permissions and limitations 

14# under the License. 

15""" 

16Affinity Weighers. Weigh hosts by the number of instances from a given host. 

17 

18AffinityWeigher implements the soft-affinity policy for server groups by 

19preferring the hosts that has more instances from the given group. 

20 

21AntiAffinityWeigher implements the soft-anti-affinity policy for server groups 

22by preferring the hosts that has less instances from the given group. 

23 

24""" 

25from oslo_config import cfg 

26from oslo_log import log as logging 

27 

28from nova.scheduler import utils 

29from nova.scheduler import weights 

30 

31CONF = cfg.CONF 

32 

33LOG = logging.getLogger(__name__) 

34 

35 

36class _SoftAffinityWeigherBase(weights.BaseHostWeigher): 

37 policy_name = None 

38 

39 def _weigh_object(self, host_state, request_spec): 

40 """Higher weights win.""" 

41 if not request_spec.instance_group: 41 ↛ 42line 41 didn't jump to line 42 because the condition on line 41 was never true

42 return 0 

43 

44 policy = request_spec.instance_group.policy 

45 

46 if self.policy_name != policy: 46 ↛ 47line 46 didn't jump to line 47 because the condition on line 46 was never true

47 return 0 

48 

49 instances = set(host_state.instances.keys()) 

50 members = set(request_spec.instance_group.members) 

51 member_on_host = instances.intersection(members) 

52 

53 return len(member_on_host) 

54 

55 

56class ServerGroupSoftAffinityWeigher(_SoftAffinityWeigherBase): 

57 policy_name = 'soft-affinity' 

58 

59 def weight_multiplier(self, host_state): 

60 return utils.get_weight_multiplier( 

61 host_state, 'soft_affinity_weight_multiplier', 

62 CONF.filter_scheduler.soft_affinity_weight_multiplier) 

63 

64 

65class ServerGroupSoftAntiAffinityWeigher(_SoftAffinityWeigherBase): 

66 policy_name = 'soft-anti-affinity' 

67 

68 def weight_multiplier(self, host_state): 

69 return utils.get_weight_multiplier( 

70 host_state, 'soft_anti_affinity_weight_multiplier', 

71 CONF.filter_scheduler.soft_anti_affinity_weight_multiplier) 

72 

73 def _weigh_object(self, host_state, request_spec): 

74 weight = super(ServerGroupSoftAntiAffinityWeigher, self)._weigh_object( 

75 host_state, request_spec) 

76 return -1 * weight