docs/scheduler/strategy/spread.go

41 lines
1.2 KiB
Go

package strategy
import (
"sort"
"github.com/docker/swarm/cluster"
"github.com/docker/swarm/scheduler/node"
)
// SpreadPlacementStrategy places a container on the node with the fewest running containers.
type SpreadPlacementStrategy struct {
}
// Initialize a SpreadPlacementStrategy.
func (p *SpreadPlacementStrategy) Initialize() error {
return nil
}
// Name returns the name of the strategy.
func (p *SpreadPlacementStrategy) Name() string {
return "spread"
}
// RankAndSort sorts nodes based on the spread strategy applied to the container config.
func (p *SpreadPlacementStrategy) RankAndSort(config *cluster.ContainerConfig, nodes []*node.Node) ([]*node.Node, error) {
// for spread, a healthy node should decrease its weight to increase its chance of being selected
// set healthFactor to -10 to make health degree [0, 100] overpower cpu + memory (each in range [0, 100])
const healthFactor int64 = -10
weightedNodes, err := weighNodes(config, nodes, healthFactor)
if err != nil {
return nil, err
}
sort.Sort(weightedNodes)
output := make([]*node.Node, len(weightedNodes))
for i, n := range weightedNodes {
output[i] = n.Node
}
return output, nil
}