Function TestRing_ShuffleShardWithLookback

pkg/ring/ring_test.go:2284–2516

(t *testing.T)

}

func TestRing_ShuffleShardWithLookback(t *testing.T) {
	type eventType int

	const (
		add eventType = iota
		remove
		test

		lookbackPeriod = time.Hour
		userID         = "user-1"
	)

	var (
		now = time.Now()
	)

	type event struct {
		what         eventType
		instanceID   string
		instanceDesc InstanceDesc
		shardSize    int
		expected     []string
	}

	tests := map[string]struct {
		timeline []event
	}{
		"single zone, shard size = 1, recently bootstrapped cluster": {
			timeline: []event{
				{what: add, instanceID: "instance-1", instanceDesc: generateRingInstanceWithInfo("instance-1", "zone-a", []uint32{userToken(userID, "zone-a", 0) + 1}, now.Add(-time.Minute))},
				{what: add, instanceID: "instance-2", instanceDesc: generateRingInstanceWithInfo("instance-2", "zone-a", []uint32{userToken(userID, "zone-a", 1) + 1}, now.Add(-time.Minute))},
				{what: add, instanceID: "instance-3", instanceDesc: generateRingInstanceWithInfo("instance-3", "zone-a", []uint32{userToken(userID, "zone-a", 2) + 1}, now.Add(-time.Minute))},
				{what: test, shardSize: 1, expected: []string{"instance-1", "instance-2", "instance-3"}},
			},
		},
		"single zone, shard size = 1, instances scale up": {
			timeline: []event{
				{what: add, instanceID: "instance-1", instanceDesc: generateRingInstanceWithInfo("instance-1", "zone-a", []uint32{userToken(userID, "zone-a", 0) + 3}, now.Add(-2*lookbackPeriod))},
				{what: add, instanceID: "instance-2", instanceDesc: generateRingInstanceWithInfo("instance-2", "zone-a", []uint32{userToken(userID, "zone-a", 1) + 1}, now.Add(-2*lookbackPeriod))},
				{what: add, instanceID: "instance-3", instanceDesc: generateRingInstanceWithInfo("instance-3", "zone-a", []uint32{userToken(userID, "zone-a", 2) + 1}, now.Add(-2*lookbackPeriod))},
				{what: test, shardSize: 1, expected: []string{"instance-1"}},
				{what: add, instanceID: "instance-4", instanceDesc: generateRingInstanceWithInfo("instance-4", "zone-a", []uint32{userToken(userID, "zone-a", 0) + 2}, now.Add(-10*time.Minute))},
				{what: test, shardSize: 1, expected: []string{"instance-4" /* lookback: */, "instance-1"}},
				{what: add, instanceID: "instance-5", instanceDesc: generateRingInstanceWithInfo("instance-5", "zone-a", []uint32{userToken(userID, "zone-a", 0) + 1}, now.Add(-5*time.Minute))},
				{what: test, shardSize: 1, expected: []string{"instance-5" /* lookback: */, "instance-4", "instance-1"}},
			},
		},
		"single zone, shard size = 1, instances scale down": {
			timeline: []event{
				{what: add, instanceID: "instance-1", instanceDesc: generateRingInstanceWithInfo("instance-1", "zone-a", []uint32{userToken(userID, "zone-a", 0) + 1}, now.Add(-2*lookbackPeriod))},
				{what: add, instanceID: "instance-2", instanceDesc: generateRingInstanceWithInfo("instance-2", "zone-a", []uint32{userToken(userID, "zone-a", 1) + 1}, now.Add(-2*lookbackPeriod))},
				{what: add, instanceID: "instance-3", instanceDesc: generateRingInstanceWithInfo("instance-3", "zone-a", []uint32{userToken(userID, "zone-a", 2) + 1}, now.Add(-2*lookbackPeriod))},
				{what: test, shardSize: 1, expected: []string{"instance-1"}},
				{what: remove, instanceID: "instance-3"},
				{what: test, shardSize: 1, expected: []string{"instance-1"}},
				{what: remove, instanceID: "instance-1"},
				{what: test, shardSize: 1, expected: []string{"instance-2"}},
			},