forked from kubernetes/kubernetes
-
Notifications
You must be signed in to change notification settings - Fork 0
/
algorithm.go
209 lines (175 loc) · 6.53 KB
/
algorithm.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
/*
Copyright 2015 The Kubernetes Authors All rights reserved.
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 algorithm
import (
"fmt"
log "github.com/golang/glog"
"k8s.io/kubernetes/contrib/mesos/pkg/offers"
"k8s.io/kubernetes/contrib/mesos/pkg/queue"
"k8s.io/kubernetes/contrib/mesos/pkg/scheduler"
"k8s.io/kubernetes/contrib/mesos/pkg/scheduler/components/algorithm/podschedulers"
"k8s.io/kubernetes/contrib/mesos/pkg/scheduler/errors"
"k8s.io/kubernetes/contrib/mesos/pkg/scheduler/podtask"
"k8s.io/kubernetes/contrib/mesos/pkg/scheduler/resources"
"k8s.io/kubernetes/pkg/api"
"k8s.io/kubernetes/pkg/client/cache"
)
// SchedulerAlgorithm is the interface that orchestrates the pod scheduling.
//
// Schedule implements the Scheduler interface of Kubernetes.
// It returns the selectedMachine's hostname or an error if the schedule failed.
type SchedulerAlgorithm interface {
Schedule(pod *api.Pod) (string, error)
}
// SchedulerAlgorithm implements the algorithm.ScheduleAlgorithm interface
type schedulerAlgorithm struct {
sched scheduler.Scheduler
podUpdates queue.FIFO
podScheduler podschedulers.PodScheduler
taskConfig podtask.Config
defaultCpus resources.CPUShares
defaultMem resources.MegaBytes
}
// New returns a new SchedulerAlgorithm
// TODO(sur): refactor params to separate config object
func New(
sched scheduler.Scheduler,
podUpdates queue.FIFO,
podScheduler podschedulers.PodScheduler,
taskConfig podtask.Config,
defaultCpus resources.CPUShares,
defaultMem resources.MegaBytes,
) SchedulerAlgorithm {
return &schedulerAlgorithm{
sched: sched,
podUpdates: podUpdates,
podScheduler: podScheduler,
taskConfig: taskConfig,
defaultCpus: defaultCpus,
defaultMem: defaultMem,
}
}
func (k *schedulerAlgorithm) Schedule(pod *api.Pod) (string, error) {
log.Infof("Try to schedule pod %v\n", pod.Name)
ctx := api.WithNamespace(api.NewDefaultContext(), pod.Namespace)
// default upstream scheduler passes pod.Name as binding.PodID
podKey, err := podtask.MakePodKey(ctx, pod.Name)
if err != nil {
return "", err
}
k.sched.Lock()
defer k.sched.Unlock()
switch task, state := k.sched.Tasks().ForPod(podKey); state {
case podtask.StateUnknown:
// There's a bit of a potential race here, a pod could have been yielded() and
// then before we get *here* it could be deleted.
// We use meta to index the pod in the store since that's what k8s reflector does.
podName, err := cache.MetaNamespaceKeyFunc(pod)
if err != nil {
log.Warningf("aborting Schedule, unable to understand pod object %+v", pod)
return "", errors.NoSuchPodErr
}
if deleted := k.podUpdates.Poll(podName, queue.DELETE_EVENT); deleted {
// avoid scheduling a pod that's been deleted between yieldPod() and Schedule()
log.Infof("aborting Schedule, pod has been deleted %+v", pod)
return "", errors.NoSuchPodErr
}
// write resource limits into the pod spec.
// From here on we can expect that the pod spec of a task has proper limits for CPU and memory.
k.limitPod(pod)
podTask, err := podtask.New(ctx, k.taskConfig, pod)
if err != nil {
log.Warningf("aborting Schedule, unable to create podtask object %+v: %v", pod, err)
return "", err
}
podTask, err = k.sched.Tasks().Register(podTask)
if err != nil {
return "", err
}
return k.doSchedule(podTask)
//TODO(jdef) it's possible that the pod state has diverged from what
//we knew previously, we should probably update the task.Pod state here
//before proceeding with scheduling
case podtask.StatePending:
if pod.UID != task.Pod.UID {
// we're dealing with a brand new pod spec here, so the old one must have been
// deleted -- and so our task store is out of sync w/ respect to reality
//TODO(jdef) reconcile task
return "", fmt.Errorf("task %v spec is out of sync with pod %v spec, aborting schedule", task.ID, pod.Name)
} else if task.Has(podtask.Launched) {
// task has been marked as "launched" but the pod binding creation may have failed in k8s,
// but we're going to let someone else handle it, probably the mesos task error handler
return "", fmt.Errorf("task %s has already been launched, aborting schedule", task.ID)
} else {
return k.doSchedule(task)
}
default:
return "", fmt.Errorf("task %s is not pending, nothing to schedule", task.ID)
}
}
// limitPod limits the given pod based on the scheduler's default limits.
func (k *schedulerAlgorithm) limitPod(pod *api.Pod) error {
cpuRequest, cpuLimit, _, err := resources.LimitPodCPU(pod, k.defaultCpus)
if err != nil {
return err
}
memRequest, memLimit, _, err := resources.LimitPodMem(pod, k.defaultMem)
if err != nil {
return err
}
log.V(3).Infof(
"setting pod %s/%s resources: requested cpu %.2f mem %.2f MB, limited cpu %.2f mem %.2f MB",
pod.Namespace, pod.Name, cpuRequest, memRequest, cpuLimit, memLimit,
)
return nil
}
// doSchedule implements the actual scheduling of the given pod task.
// It checks whether the offer has been accepted and is still present in the offer registry.
// It delegates to the actual pod scheduler and updates the task registry.
func (k *schedulerAlgorithm) doSchedule(task *podtask.T) (string, error) {
var offer offers.Perishable
var err error
if task.HasAcceptedOffer() {
// verify that the offer is still on the table
var ok bool
offer, ok = k.sched.Offers().Get(task.GetOfferId())
if !ok || offer.HasExpired() {
task.Offer.Release()
task.Reset()
if err = k.sched.Tasks().Update(task); err != nil {
return "", err
}
}
}
var spec *podtask.Spec
if offer == nil {
offer, spec, err = k.podScheduler.SchedulePod(k.sched.Offers(), task)
}
if err != nil {
return "", err
}
details := offer.Details()
if details == nil {
return "", fmt.Errorf("offer already invalid/expired for task %v", task.ID)
}
if task.Offer != nil && task.Offer != offer {
return "", fmt.Errorf("task.offer assignment must be idempotent, task %+v: offer %+v", task, offer)
}
task.Offer = offer
task.Spec = spec
if err := k.sched.Tasks().Update(task); err != nil {
offer.Release()
return "", err
}
return details.GetHostname(), nil
}