forked from kubernetes/kubernetes
-
Notifications
You must be signed in to change notification settings - Fork 1
/
scheduler.go
226 lines (196 loc) · 8.08 KB
/
scheduler.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
/*
Copyright 2014 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 scheduler
import (
"time"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/util/wait"
"k8s.io/kubernetes/pkg/api/v1"
"k8s.io/kubernetes/pkg/client/record"
"k8s.io/kubernetes/plugin/pkg/scheduler/algorithm"
schedulerapi "k8s.io/kubernetes/plugin/pkg/scheduler/api"
"k8s.io/kubernetes/plugin/pkg/scheduler/metrics"
"k8s.io/kubernetes/plugin/pkg/scheduler/schedulercache"
"k8s.io/kubernetes/plugin/pkg/scheduler/util"
clientset "k8s.io/kubernetes/pkg/client/clientset_generated/clientset"
"github.com/golang/glog"
"k8s.io/apimachinery/pkg/util/sets"
"k8s.io/client-go/tools/cache"
)
// Binder knows how to write a binding.
type Binder interface {
Bind(binding *v1.Binding) error
}
type PodConditionUpdater interface {
Update(pod *v1.Pod, podCondition *v1.PodCondition) error
}
// Scheduler watches for new unscheduled pods. It attempts to find
// nodes that they fit on and writes bindings back to the api server.
type Scheduler struct {
config *Config
}
func (sched *Scheduler) StopEverything() {
close(sched.config.StopEverything)
}
// These are the functions which need to be provided in order to build a Scheduler configuration.
// An implementation of this can be seen in factory.go.
type Configurator interface {
GetPriorityFunctionConfigs(priorityKeys sets.String) ([]algorithm.PriorityConfig, error)
GetPriorityMetadataProducer() (algorithm.MetadataProducer, error)
GetPredicateMetadataProducer() (algorithm.MetadataProducer, error)
GetPredicates(predicateKeys sets.String) (map[string]algorithm.FitPredicate, error)
GetHardPodAffinitySymmetricWeight() int
GetFailureDomains() []string
GetSchedulerName() string
MakeDefaultErrorFunc(backoff *util.PodBackoff, podQueue *cache.FIFO) func(pod *v1.Pod, err error)
// Probably doesn't need to be public. But exposed for now in case.
ResponsibleForPod(pod *v1.Pod) bool
// Needs to be exposed for things like integration tests where we want to make fake nodes.
GetNodeStore() cache.Store
GetClient() clientset.Interface
GetScheduledPodListerIndexer() cache.Indexer
Run()
Create() (*Config, error)
CreateFromProvider(providerName string) (*Config, error)
CreateFromConfig(policy schedulerapi.Policy) (*Config, error)
CreateFromKeys(predicateKeys, priorityKeys sets.String, extenders []algorithm.SchedulerExtender) (*Config, error)
}
// TODO over time we should make this struct a hidden implementation detail of the scheduler.
type Config struct {
// It is expected that changes made via SchedulerCache will be observed
// by NodeLister and Algorithm.
SchedulerCache schedulercache.Cache
NodeLister algorithm.NodeLister
Algorithm algorithm.ScheduleAlgorithm
Binder Binder
// PodConditionUpdater is used only in case of scheduling errors. If we succeed
// with scheduling, PodScheduled condition will be updated in apiserver in /bind
// handler so that binding and setting PodCondition it is atomic.
PodConditionUpdater PodConditionUpdater
// NextPod should be a function that blocks until the next pod
// is available. We don't use a channel for this, because scheduling
// a pod may take some amount of time and we don't want pods to get
// stale while they sit in a channel.
NextPod func() *v1.Pod
// Error is called if there is an error. It is passed the pod in
// question, and the error
Error func(*v1.Pod, error)
// Recorder is the EventRecorder to use
Recorder record.EventRecorder
// Close this to shut down the scheduler.
StopEverything chan struct{}
}
// New returns a new scheduler.
// TODO replace this with NewFromConfigurator.
func New(c *Config) *Scheduler {
s := &Scheduler{
config: c,
}
metrics.Register()
return s
}
// NewFromConfigurator returns a new scheduler that is created entirely by the Configurator. Assumes Create() is implemented.
// Supports intermediate Config mutation for now if you provide modifier functions which will run after Config is created.
func NewFromConfigurator(c Configurator, modifiers ...func(c *Config)) (*Scheduler, error) {
cfg, err := c.Create()
if err != nil {
return nil, err
}
// Mutate it if any functions were provided, changes might be required for certain types of tests (i.e. change the recorder).
for _, modifier := range modifiers {
modifier(cfg)
}
// From this point on the config is immutable to the outside.
s := &Scheduler{
config: cfg,
}
metrics.Register()
return s, nil
}
// Run begins watching and scheduling. It starts a goroutine and returns immediately.
func (s *Scheduler) Run() {
go wait.Until(s.scheduleOne, 0, s.config.StopEverything)
}
func (s *Scheduler) scheduleOne() {
pod := s.config.NextPod()
if pod.DeletionTimestamp != nil {
s.config.Recorder.Eventf(pod, v1.EventTypeWarning, "FailedScheduling", "skip schedule deleting pod: %v/%v", pod.Namespace, pod.Name)
glog.V(3).Infof("Skip schedule deleting pod: %v/%v", pod.Namespace, pod.Name)
return
}
glog.V(3).Infof("Attempting to schedule pod: %v/%v", pod.Namespace, pod.Name)
start := time.Now()
dest, err := s.config.Algorithm.Schedule(pod, s.config.NodeLister)
if err != nil {
glog.V(1).Infof("Failed to schedule pod: %v/%v", pod.Namespace, pod.Name)
s.config.Error(pod, err)
s.config.Recorder.Eventf(pod, v1.EventTypeWarning, "FailedScheduling", "%v", err)
s.config.PodConditionUpdater.Update(pod, &v1.PodCondition{
Type: v1.PodScheduled,
Status: v1.ConditionFalse,
Reason: v1.PodReasonUnschedulable,
Message: err.Error(),
})
return
}
metrics.SchedulingAlgorithmLatency.Observe(metrics.SinceInMicroseconds(start))
// Optimistically assume that the binding will succeed and send it to apiserver
// in the background.
// If the binding fails, scheduler will release resources allocated to assumed pod
// immediately.
assumed := *pod
assumed.Spec.NodeName = dest
if err := s.config.SchedulerCache.AssumePod(&assumed); err != nil {
glog.Errorf("scheduler cache AssumePod failed: %v", err)
// TODO: This means that a given pod is already in cache (which means it
// is either assumed or already added). This is most probably result of a
// BUG in retrying logic. As a temporary workaround (which doesn't fully
// fix the problem, but should reduce its impact), we simply return here,
// as binding doesn't make sense anyway.
// This should be fixed properly though.
return
}
go func() {
defer metrics.E2eSchedulingLatency.Observe(metrics.SinceInMicroseconds(start))
b := &v1.Binding{
ObjectMeta: metav1.ObjectMeta{Namespace: pod.Namespace, Name: pod.Name},
Target: v1.ObjectReference{
Kind: "Node",
Name: dest,
},
}
bindingStart := time.Now()
// If binding succeeded then PodScheduled condition will be updated in apiserver so that
// it's atomic with setting host.
err := s.config.Binder.Bind(b)
if err := s.config.SchedulerCache.FinishBinding(&assumed); err != nil {
glog.Errorf("scheduler cache FinishBinding failed: %v", err)
}
if err != nil {
glog.V(1).Infof("Failed to bind pod: %v/%v", pod.Namespace, pod.Name)
if err := s.config.SchedulerCache.ForgetPod(&assumed); err != nil {
glog.Errorf("scheduler cache ForgetPod failed: %v", err)
}
s.config.Error(pod, err)
s.config.Recorder.Eventf(pod, v1.EventTypeNormal, "FailedScheduling", "Binding rejected: %v", err)
s.config.PodConditionUpdater.Update(pod, &v1.PodCondition{
Type: v1.PodScheduled,
Status: v1.ConditionFalse,
Reason: "BindingRejected",
})
return
}
metrics.BindingLatency.Observe(metrics.SinceInMicroseconds(bindingStart))
s.config.Recorder.Eventf(pod, v1.EventTypeNormal, "Scheduled", "Successfully assigned %v to %v", pod.Name, dest)
}()
}