docs/scheduler/strategy/binpack_test.go

package strategy

import (
	"fmt"
	"testing"

	"github.com/docker/swarm/cluster"
	"github.com/docker/swarm/scheduler/node"
	"github.com/samalba/dockerclient"
	"github.com/stretchr/testify/assert"
)

func createNode(ID string, memory int64, cpus int64) *node.Node {
	oc := 0.05
	memory = int64(float64(memory) + float64(memory)*oc)
	return &node.Node{
		ID:          ID,
		IP:          ID,
		Addr:        ID,
		TotalMemory: memory * 1024 * 1024 * 1024,
		TotalCpus:   cpus,
	}
}

func createConfig(memory int64, cpus int64) *dockerclient.ContainerConfig {
	return &dockerclient.ContainerConfig{Memory: memory * 1024 * 1024 * 1024, CpuShares: cpus}
}

func createContainer(ID string, config *dockerclient.ContainerConfig) *cluster.Container {
	return &cluster.Container{Container: dockerclient.Container{Id: ID}, Info: dockerclient.ContainerInfo{Config: config}}
}

func TestPlaceEqualWeight(t *testing.T) {
	s := &BinpackPlacementStrategy{}

	nodes := []*node.Node{}
	for i := 0; i < 2; i++ {
		nodes = append(nodes, createNode(fmt.Sprintf("node-%d", i), 4, 0))
	}

	// add 1 container 2G on node1
	config := createConfig(2, 0)
	assert.NoError(t, nodes[0].AddContainer(createContainer("c1", config)))
	assert.Equal(t, nodes[0].UsedMemory, 2*1024*1024*1024)

	// add 2 containers 1G on node2
	config = createConfig(1, 0)
	assert.NoError(t, nodes[1].AddContainer(createContainer("c2", config)))
	assert.NoError(t, nodes[1].AddContainer(createContainer("c3", config)))
	assert.Equal(t, nodes[1].UsedMemory, int64(2*1024*1024*1024))

	// add another container 1G
	config = createConfig(1, 0)
	node, err := s.PlaceContainer(config, nodes)
	assert.NoError(t, err)
	assert.NoError(t, node.AddContainer(createContainer("c4", config)))
	assert.Equal(t, node.UsedMemory, 3*1024*1024*1024)

	// check that the last container ended on the node with the highest number of containers
	assert.Equal(t, node.ID, nodes[1].ID)
	assert.NotEqual(t, len(nodes[0].Containers), len(nodes[1].Containers))

}

func TestPlaceContainerMemory(t *testing.T) {
	s := &BinpackPlacementStrategy{}

	nodes := []*node.Node{}
	for i := 0; i < 2; i++ {
		nodes = append(nodes, createNode(fmt.Sprintf("node-%d", i), 2, 0))
	}

	// add 1 container 1G
	config := createConfig(1, 0)
	node1, err := s.PlaceContainer(config, nodes)
	assert.NoError(t, err)
	assert.NoError(t, node1.AddContainer(createContainer("c1", config)))
	assert.Equal(t, node1.UsedMemory, 1024*1024*1024)

	// add another container 1G
	config = createConfig(1, 0)
	node2, err := s.PlaceContainer(config, nodes)
	assert.NoError(t, err)
	assert.NoError(t, node2.AddContainer(createContainer("c2", config)))
	assert.Equal(t, node2.UsedMemory, int64(2*1024*1024*1024))

	// check that both containers ended on the same node
	assert.Equal(t, node1.ID, node2.ID)
	assert.Equal(t, len(node1.Containers), len(node2.Containers))
}

func TestPlaceContainerCPU(t *testing.T) {
	s := &BinpackPlacementStrategy{}

	nodes := []*node.Node{}
	for i := 0; i < 2; i++ {
		nodes = append(nodes, createNode(fmt.Sprintf("node-%d", i), 0, 2))
	}

	// add 1 container 1CPU
	config := createConfig(0, 1)
	node1, err := s.PlaceContainer(config, nodes)
	assert.NoError(t, err)
	assert.NoError(t, node1.AddContainer(createContainer("c1", config)))
	assert.Equal(t, node1.UsedCpus, 1)

	// add another container 1CPU
	config = createConfig(0, 1)
	node2, err := s.PlaceContainer(config, nodes)
	assert.NoError(t, err)
	assert.NoError(t, node2.AddContainer(createContainer("c2", config)))
	assert.Equal(t, node2.UsedCpus, 2)

	// check that both containers ended on the same node
	assert.Equal(t, node1.ID, node2.ID)
	assert.Equal(t, len(node1.Containers), len(node2.Containers))
}

func TestPlaceContainerHuge(t *testing.T) {
	s := &BinpackPlacementStrategy{}

	nodes := []*node.Node{}
	for i := 0; i < 100; i++ {
		nodes = append(nodes, createNode(fmt.Sprintf("node-%d", i), 1, 1))
	}

	// add 100 container 1CPU
	for i := 0; i < 100; i++ {
		node, err := s.PlaceContainer(createConfig(0, 1), nodes)
		assert.NoError(t, err)
		assert.NoError(t, node.AddContainer(createContainer(fmt.Sprintf("c%d", i), createConfig(0, 1))))
	}

	// try to add another container 1CPU
	_, err := s.PlaceContainer(createConfig(0, 1), nodes)
	assert.Error(t, err)

	// add 100 container 1G
	for i := 100; i < 200; i++ {
		node, err := s.PlaceContainer(createConfig(1, 0), nodes)
		assert.NoError(t, err)
		assert.NoError(t, node.AddContainer(createContainer(fmt.Sprintf("c%d", i), createConfig(1, 0))))
	}

	// try to add another container 1G
	_, err = s.PlaceContainer(createConfig(1, 0), nodes)
	assert.Error(t, err)
}

func TestPlaceContainerOvercommit(t *testing.T) {
	s, err := New("binpacking")
	assert.NoError(t, err)

	nodes := []*node.Node{createNode("node-1", 100, 1)}

	config := createConfig(0, 0)

	// Below limit should still work.
	config.Memory = 90 * 1024 * 1024 * 1024
	node, err := s.PlaceContainer(config, nodes)
	assert.NoError(t, err)
	assert.Equal(t, node, nodes[0])

	// At memory limit should still work.
	config.Memory = 100 * 1024 * 1024 * 1024
	node, err = s.PlaceContainer(config, nodes)
	assert.NoError(t, err)
	assert.Equal(t, node, nodes[0])

	// Up to 105% it should still work.
	config.Memory = 105 * 1024 * 1024 * 1024
	node, err = s.PlaceContainer(config, nodes)
	assert.NoError(t, err)
	assert.Equal(t, node, nodes[0])

	// Above it should return an error.
	config.Memory = 106 * 1024 * 1024 * 1024
	node, err = s.PlaceContainer(config, nodes)
	assert.Error(t, err)
}

// The demo
func TestPlaceContainerDemo(t *testing.T) {
	s := &BinpackPlacementStrategy{}

	nodes := []*node.Node{}
	for i := 0; i < 3; i++ {
		nodes = append(nodes, createNode(fmt.Sprintf("node-%d", i), 2, 4))
	}

	// try to place a 10G container
	config := createConfig(10, 0)
	_, err := s.PlaceContainer(config, nodes)

	// check that it refuses because the cluster is full
	assert.Error(t, err)

	// add one container 1G
	config = createConfig(1, 0)
	node1, err := s.PlaceContainer(config, nodes)
	assert.NoError(t, err)
	assert.NoError(t, node1.AddContainer(createContainer("c1", config)))
	// add another container 1G
	config = createConfig(1, 0)
	node1bis, err := s.PlaceContainer(config, nodes)
	assert.NoError(t, err)
	assert.NoError(t, node1bis.AddContainer(createContainer("c2", config)))

	// check that both containers ended on the same node
	assert.Equal(t, node1.ID, node1bis.ID)
	assert.Equal(t, len(node1.Containers), len(node1bis.Containers))

	// add another container 2G
	config = createConfig(2, 0)
	node2, err := s.PlaceContainer(config, nodes)
	assert.NoError(t, err)
	assert.NoError(t, node2.AddContainer(createContainer("c3", config)))

	// check that it ends up on another node
	assert.NotEqual(t, node1.ID, node2.ID)

	// add another container 1G
	config = createConfig(1, 0)
	node3, err := s.PlaceContainer(config, nodes)
	assert.NoError(t, err)
	assert.NoError(t, node3.AddContainer(createContainer("c4", config)))

	// check that it ends up on another node
	assert.NotEqual(t, node1.ID, node3.ID)
	assert.NotEqual(t, node2.ID, node3.ID)

	// add another container 1G
	config = createConfig(1, 0)
	node3bis, err := s.PlaceContainer(config, nodes)
	assert.NoError(t, err)
	assert.NoError(t, node3bis.AddContainer(createContainer("c5", config)))

	// check that it ends up on the same node
	assert.Equal(t, node3.ID, node3bis.ID)

	// try to add another container
	config = createConfig(1, 0)
	_, err = s.PlaceContainer(config, nodes)

	// check that it refuses because the cluster is full
	assert.Error(t, err)

	// remove container in the middle
	node2.Containers = nil
	node2.UsedMemory = 0
	node2.UsedCpus = 0

	// add another container
	config = createConfig(1, 0)
	node2bis, err := s.PlaceContainer(config, nodes)
	assert.NoError(t, err)
	assert.NoError(t, node2bis.AddContainer(createContainer("c6", config)))

	// check it ends up on `node3`
	assert.Equal(t, node2.ID, node2bis.ID)
	assert.Equal(t, len(node2.Containers), len(node2bis.Containers))
}

func TestComplexPlacement(t *testing.T) {
	s := &BinpackPlacementStrategy{}

	nodes := []*node.Node{}
	for i := 0; i < 2; i++ {
		nodes = append(nodes, createNode(fmt.Sprintf("node-%d", i), 4, 4))
	}

	// add one container 2G
	config := createConfig(2, 0)
	node1, err := s.PlaceContainer(config, nodes)
	assert.NoError(t, err)
	assert.NoError(t, node1.AddContainer(createContainer("c1", config)))

	// add one container 3G
	config = createConfig(3, 0)
	node2, err := s.PlaceContainer(config, nodes)
	assert.NoError(t, err)
	assert.NoError(t, node2.AddContainer(createContainer("c2", config)))

	// check that they end up on separate nodes
	assert.NotEqual(t, node1.ID, node2.ID)

	// add one container 1G
	config = createConfig(1, 0)
	node3, err := s.PlaceContainer(config, nodes)
	assert.NoError(t, err)
	assert.NoError(t, node3.AddContainer(createContainer("c3", config)))

	// check that it ends up on the same node as the 3G
	assert.Equal(t, node2.ID, node3.ID)
}