116 lines
2.9 KiB
Go
116 lines
2.9 KiB
Go
/*
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Copyright 2014 Google Inc. All rights reserved.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package registry
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import (
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"fmt"
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"math/rand"
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. "github.com/GoogleCloudPlatform/kubernetes/pkg/api"
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)
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// Scheduler is an interface implemented by things that know how to schedule tasks onto machines.
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type Scheduler interface {
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Schedule(Task) (string, error)
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}
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// RandomScheduler choses machines uniformly at random.
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type RandomScheduler struct {
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machines []string
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random rand.Rand
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}
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func MakeRandomScheduler(machines []string, random rand.Rand) Scheduler {
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return &RandomScheduler{
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machines: machines,
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random: random,
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}
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}
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func (s *RandomScheduler) Schedule(task Task) (string, error) {
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return s.machines[s.random.Int()%len(s.machines)], nil
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}
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// RoundRobinScheduler chooses machines in order.
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type RoundRobinScheduler struct {
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machines []string
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currentIndex int
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}
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func MakeRoundRobinScheduler(machines []string) Scheduler {
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return &RoundRobinScheduler{
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machines: machines,
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currentIndex: 0,
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}
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}
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func (s *RoundRobinScheduler) Schedule(task Task) (string, error) {
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result := s.machines[s.currentIndex]
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s.currentIndex = (s.currentIndex + 1) % len(s.machines)
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return result, nil
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}
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type FirstFitScheduler struct {
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machines []string
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registry TaskRegistry
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}
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func MakeFirstFitScheduler(machines []string, registry TaskRegistry) Scheduler {
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return &FirstFitScheduler{
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machines: machines,
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registry: registry,
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}
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}
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func (s *FirstFitScheduler) containsPort(task Task, port Port) bool {
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for _, container := range task.DesiredState.Manifest.Containers {
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for _, taskPort := range container.Ports {
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if taskPort.HostPort == port.HostPort {
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return true
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}
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}
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}
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return false
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}
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func (s *FirstFitScheduler) Schedule(task Task) (string, error) {
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machineToTasks := map[string][]Task{}
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tasks, err := s.registry.ListTasks(nil)
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if err != nil {
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return "", err
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}
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for _, scheduledTask := range tasks {
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host := scheduledTask.CurrentState.Host
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machineToTasks[host] = append(machineToTasks[host], scheduledTask)
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}
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for _, machine := range s.machines {
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taskFits := true
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for _, scheduledTask := range machineToTasks[machine] {
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for _, container := range task.DesiredState.Manifest.Containers {
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for _, port := range container.Ports {
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if s.containsPort(scheduledTask, port) {
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taskFits = false
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}
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}
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}
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}
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if taskFits {
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return machine, nil
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}
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}
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return "", fmt.Errorf("Failed to find fit for %#v", task)
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}
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