/
topology_manager.go
293 lines (249 loc) · 9.97 KB
/
topology_manager.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
/*
Copyright 2019 The Kubernetes Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package topologymanager
import (
"fmt"
"k8s.io/api/core/v1"
"k8s.io/klog"
"k8s.io/kubernetes/pkg/kubelet/cm/topologymanager/socketmask"
"k8s.io/kubernetes/pkg/kubelet/lifecycle"
)
//Manager interface provides methods for Kubelet to manage pod topology hints
type Manager interface {
//Manager implements pod admit handler interface
lifecycle.PodAdmitHandler
//Adds a hint provider to manager to indicate the hint provider
//wants to be consoluted when making topology hints
AddHintProvider(HintProvider)
//Adds pod to Manager for tracking
AddContainer(pod *v1.Pod, containerID string) error
//Removes pod from Manager tracking
RemoveContainer(containerID string) error
//Interface for storing pod topology hints
Store
}
type manager struct {
//The list of components registered with the Manager
hintProviders []HintProvider
//Mapping of a Pods mapping of Containers and their TopologyHints
//Indexed by PodUID to ContainerName
podTopologyHints map[string]map[string]TopologyHint
//Mapping of PodUID to ContainerID for Adding/Removing Pods from PodTopologyHints mapping
podMap map[string]string
//Topology Manager Policy
policy Policy
}
//HintProvider interface is to be implemented by Hint Providers
type HintProvider interface {
GetTopologyHints(pod v1.Pod, container v1.Container) []TopologyHint
}
//Store interface is to allow Hint Providers to retrieve pod affinity
type Store interface {
GetAffinity(podUID string, containerName string) TopologyHint
}
//TopologyHint is a struct containing a SocketMask for a Container
type TopologyHint struct {
SocketAffinity socketmask.SocketMask
// Preferred is set to true when the SocketMask encodes a preferred
// allocation for the Container. It is set to false otherwise.
Preferred bool
}
var _ Manager = &manager{}
//NewManager creates a new TopologyManager based on provided policy
func NewManager(topologyPolicyName string) (Manager, error) {
klog.Infof("[topologymanager] Creating topology manager with %s policy", topologyPolicyName)
var policy Policy
switch topologyPolicyName {
case PolicyNone:
policy = NewNonePolicy()
case PolicyBestEffort:
policy = NewBestEffortPolicy()
case PolicyStrict:
policy = NewStrictPolicy()
default:
return nil, fmt.Errorf("unknown policy: \"%s\"", topologyPolicyName)
}
var hp []HintProvider
pth := make(map[string]map[string]TopologyHint)
pm := make(map[string]string)
manager := &manager{
hintProviders: hp,
podTopologyHints: pth,
podMap: pm,
policy: policy,
}
return manager, nil
}
func (m *manager) GetAffinity(podUID string, containerName string) TopologyHint {
return m.podTopologyHints[podUID][containerName]
}
// Iterate over all permutations of hints in 'allProviderHints [][]TopologyHint'.
//
// This procedure is implemented as a recursive function over the set of hints
// in 'allproviderHints[i]'. It applies the function 'callback' to each
// permutation as it is found. It is the equivalent of:
//
// for i := 0; i < len(providerHints[0]); i++
// for j := 0; j < len(providerHints[1]); j++
// for k := 0; k < len(providerHints[2]); k++
// ...
// for z := 0; z < len(providerHints[-1]); z++
// permutation := []TopologyHint{
// providerHints[0][i],
// providerHints[1][j],
// providerHints[2][k],
// ...
// provideryHints[-1][z]
// }
// callback(permutation)
func (m *manager) iterateAllProviderTopologyHints(allProviderHints [][]TopologyHint, callback func([]TopologyHint)) {
// Internal helper function to accumulate the permutation before calling the callback.
var iterate func(i int, accum []TopologyHint)
iterate = func(i int, accum []TopologyHint) {
// Base case: we have looped through all providers and have a full permutation.
if i == len(allProviderHints) {
callback(accum)
return
}
// Loop through all hints for provider 'i', and recurse to build the
// the permutation of this hint with all hints from providers 'i++'.
for j := range allProviderHints[i] {
iterate(i+1, append(accum, allProviderHints[i][j]))
}
}
iterate(0, []TopologyHint{})
}
// Merge the hints from all hint providers to find the best one.
func (m *manager) calculateAffinity(pod v1.Pod, container v1.Container) TopologyHint {
// Set the default hint to return from this function as an any-socket
// affinity with an unpreferred allocation. This will only be returned if
// no better hint can be found when merging hints from each hint provider.
defaultAffinity, _ := socketmask.NewSocketMask()
defaultAffinity.Fill()
defaultHint := TopologyHint{defaultAffinity, false}
// Loop through all hint providers and save an accumulated list of the
// hints returned by each hint provider. If no hints are provided, assume
// that provider has no preference for topology-aware allocation.
var allProviderHints [][]TopologyHint
for _, provider := range m.hintProviders {
// Get the TopologyHints from a provider.
hints := provider.GetTopologyHints(pod, container)
// If hints is nil, overwrite 'hints' with a preferred any-socket affinity.
if hints == nil || len(hints) == 0 {
klog.Infof("[topologymanager] Hint Provider has no preference for socket affinity")
affinity, _ := socketmask.NewSocketMask()
affinity.Fill()
hints = []TopologyHint{{affinity, true}}
}
// Accumulate the sorted hints into a [][]TopologyHint slice
allProviderHints = append(allProviderHints, hints)
}
// Iterate over all permutations of hints in 'allProviderHints'. Merge the
// hints in each permutation by taking the bitwise-and of their affinity masks.
// Return the hint with the narrowest SocketAffinity of all merged
// permutations that have at least one socket set. If no merged mask can be
// found that has at least one socket set, return the 'defaultHint'.
bestHint := defaultHint
m.iterateAllProviderTopologyHints(allProviderHints, func(permutation []TopologyHint) {
// Get the SocketAffinity from each hint in the permutation and see if any
// of them encode unpreferred allocations.
preferred := true
var socketAffinities []socketmask.SocketMask
for _, hint := range permutation {
// Only consider hints that have an actual SocketAffinity set.
if hint.SocketAffinity != nil {
if !hint.Preferred {
preferred = false
}
socketAffinities = append(socketAffinities, hint.SocketAffinity)
}
}
// Merge the affinities using a bitwise-and operation.
mergedAffinity, _ := socketmask.NewSocketMask()
mergedAffinity.Fill()
mergedAffinity.And(socketAffinities...)
// Build a mergedHintfrom the merged affinity mask, indicating if an
// preferred allocation was used to generate the affinity mask or not.
mergedHint := TopologyHint{mergedAffinity, preferred}
// Only consider mergedHints that result in a SocketAffinity > 0 to
// replace the current bestHint.
if mergedHint.SocketAffinity.Count() == 0 {
return
}
// If the current bestHint is non-preferred and the new mergedHint is
// preferred, always choose the preferred hint over the non-preferred one.
if mergedHint.Preferred && !bestHint.Preferred {
bestHint = mergedHint
return
}
// If the current bestHint is preferred and the new mergedHint is
// non-preferred, never update bestHint, regardless of mergedHint's
// narowness.
if !mergedHint.Preferred && bestHint.Preferred {
return
}
// If mergedHint and bestHint has the same preference, only consider
// mergedHints that have a narrower SocketAffinity than the
// SocketAffinity in the current bestHint.
if !mergedHint.SocketAffinity.IsNarrowerThan(bestHint.SocketAffinity) {
return
}
// In all other cases, update bestHint to the current mergedHint
bestHint = mergedHint
})
klog.Infof("[topologymanager] ContainerTopologyHint: %v", bestHint)
return bestHint
}
func (m *manager) AddHintProvider(h HintProvider) {
m.hintProviders = append(m.hintProviders, h)
}
func (m *manager) AddContainer(pod *v1.Pod, containerID string) error {
m.podMap[containerID] = string(pod.UID)
return nil
}
func (m *manager) RemoveContainer(containerID string) error {
podUIDString := m.podMap[containerID]
delete(m.podTopologyHints, podUIDString)
delete(m.podMap, containerID)
klog.Infof("[topologymanager] RemoveContainer - Container ID: %v podTopologyHints: %v", containerID, m.podTopologyHints)
return nil
}
func (m *manager) Admit(attrs *lifecycle.PodAdmitAttributes) lifecycle.PodAdmitResult {
klog.Infof("[topologymanager] Topology Admit Handler")
if m.policy.Name() == "none" {
klog.Infof("[topologymanager] Skipping calculate topology affinity as policy: none")
return lifecycle.PodAdmitResult{
Admit: true,
}
}
pod := attrs.Pod
c := make(map[string]TopologyHint)
klog.Infof("[topologymanager] Pod QoS Level: %v", pod.Status.QOSClass)
if pod.Status.QOSClass == v1.PodQOSGuaranteed {
for _, container := range append(pod.Spec.InitContainers, pod.Spec.Containers...) {
result := m.calculateAffinity(*pod, container)
admitPod := m.policy.CanAdmitPodResult(result.Preferred)
if admitPod.Admit == false {
return admitPod
}
c[container.Name] = result
}
m.podTopologyHints[string(pod.UID)] = c
klog.Infof("[topologymanager] Topology Affinity for Pod: %v are %v", pod.UID, m.podTopologyHints[string(pod.UID)])
} else {
klog.Infof("[topologymanager] Topology Manager only affinitises Guaranteed pods.")
}
return lifecycle.PodAdmitResult{
Admit: true,
}
}