func (sender *Sender) sendStartMessage(startMessage models.PendingStartMessage) {
	messageToSend, shouldSend := sender.startMessageToSend(startMessage)
	if shouldSend {
		if sender.numberOfStartMessagesSent < sender.conf.SenderMessageLimit {
			sender.logger.Info("Sending message", startMessage.LogDescription())
			err := sender.messageBus.Publish(sender.conf.SenderNatsStartSubject, messageToSend.ToJSON())

			if err != nil {
				sender.logger.Error("Failed to send start message", err, startMessage.LogDescription())
				sender.didSucceed = false
				return
			}

			sender.sentStartMessages = append(sender.sentStartMessages, startMessage)

			if startMessage.KeepAlive == 0 {
				sender.queueStartMessageForDeletion(startMessage, "a sent start message with no keep alive")
			} else {
				sender.markStartMessageSent(startMessage)
			}

			sender.numberOfStartMessagesSent += 1
		}
	} else {
		sender.queueStartMessageForDeletion(startMessage, "start message that will not be sent")
	}
}

func (a *appAnalyzer) appendStartMessageIfNotDuplicate(message models.PendingStartMessage, loggingMessage string, additionalDetails map[string]string) (didAppend bool) {
	existingMessage, alreadyQueued := a.existingPendingStartMessages[message.StoreKey()]
	if !alreadyQueued {
		a.logger.Info(fmt.Sprintf("Enqueuing Start Message: %s", loggingMessage), message.LogDescription(), additionalDetails)
		a.startMessages[message.StoreKey()] = message
		return true
	} else {
		a.logger.Info(fmt.Sprintf("Skipping Already Enqueued Start Message: %s", loggingMessage), existingMessage.LogDescription(), additionalDetails)
		return false
	}
}

func (sender *Sender) startMessageToSend(message models.PendingStartMessage) (models.StartMessage, bool) {
	messageToSend := models.StartMessage{
		MessageId:     message.MessageId,
		AppGuid:       message.AppGuid,
		AppVersion:    message.AppVersion,
		InstanceIndex: message.IndexToStart,
	}

	if message.SkipVerification {
		sender.logger.Info("Sending start message: message is marked with SkipVerification", message.LogDescription())
		return messageToSend, true
	}

	appKey := sender.store.AppKey(message.AppGuid, message.AppVersion)
	app, found := sender.apps[appKey]

	if !found {
		sender.logger.Info("Skipping sending start message: app is no longer desired", message.LogDescription())
		return models.StartMessage{}, false
	}

	if !app.IsDesired() {
		sender.logger.Info("Skipping sending start message: app is no longer desired", message.LogDescription(), app.LogDescription())
		return models.StartMessage{}, false
	}

	if !app.IsIndexDesired(message.IndexToStart) {
		sender.logger.Info("Skipping sending start message: instance index is beyond the desired # of instances", message.LogDescription(), app.LogDescription())
		return models.StartMessage{}, false
	}

	if app.HasStartingOrRunningInstanceAtIndex(message.IndexToStart) {
		sender.logger.Info("Skipping sending start message: instance is already running", message.LogDescription(), app.LogDescription())
		return models.StartMessage{}, false
	}

	sender.logger.Info("Sending start message: instance is not running at desired index", message.LogDescription(), app.LogDescription())
	return messageToSend, true
}

func (sender *Sender) queueStartMessageForDeletion(startMessage models.PendingStartMessage, reason string) {
	sender.logger.Info(fmt.Sprintf("Deleting %s", reason), startMessage.LogDescription())
	sender.startMessagesToDelete = append(sender.startMessagesToDelete, startMessage)
}

func (sender *Sender) markStartMessageSent(startMessage models.PendingStartMessage) {
	startMessage.SentOn = sender.timeProvider.Time().Unix()
	sender.startMessagesToSave = append(sender.startMessagesToSave, startMessage)
}

func (sender *Sender) markStartMessageSent(startMessage models.PendingStartMessage) {
	startMessage.SentOn = sender.currentTime.Unix()
	sender.startMessagesToSave = append(sender.startMessagesToSave, startMessage)
}

	"github.com/cloudfoundry/hm9000/models"
	. "github.com/cloudfoundry/hm9000/store"
	"github.com/cloudfoundry/hm9000/testhelpers/fakelogger"
	"github.com/cloudfoundry/storeadapter"
	"github.com/cloudfoundry/storeadapter/etcdstoreadapter"
	"github.com/cloudfoundry/storeadapter/storenodematchers"
	"github.com/cloudfoundry/storeadapter/workerpool"
	. "github.com/onsi/ginkgo"
	. "github.com/onsi/gomega"
)

var _ = Describe("Storing PendingStartMessages", func() {
	var (
		store        Store
		storeAdapter storeadapter.StoreAdapter
		conf         *config.Config
		message1     models.PendingStartMessage
		message2     models.PendingStartMessage
		message3     models.PendingStartMessage
	)

	BeforeEach(func() {
		var err error
		conf, err = config.DefaultConfig()
		Ω(err).ShouldNot(HaveOccurred())
		storeAdapter = etcdstoreadapter.NewETCDStoreAdapter(etcdRunner.NodeURLS(), workerpool.NewWorkerPool(conf.StoreMaxConcurrentRequests))
		err = storeAdapter.Connect()
		Ω(err).ShouldNot(HaveOccurred())

		message1 = models.NewPendingStartMessage(time.Unix(100, 0), 10, 4, "ABC", "123", 1, 1.0, models.PendingStartMessageReasonInvalid)
		message2 = models.NewPendingStartMessage(time.Unix(100, 0), 10, 4, "DEF", "123", 1, 1.0, models.PendingStartMessageReasonInvalid)
		message3 = models.NewPendingStartMessage(time.Unix(100, 0), 10, 4, "ABC", "456", 1, 1.0, models.PendingStartMessageReasonInvalid)

		})
	})

	Context("when there are no stop messages in the queue", func() {
		It("should not send any messages", func() {
			err := sender.Send()
			Ω(err).ShouldNot(HaveOccurred())
			Ω(messageBus.PublishedMessages).Should(BeEmpty())
		})
	})

	Context("when there are start messages", func() {
		var keepAliveTime int
		var sentOn int64
		var err error
		var pendingMessage models.PendingStartMessage
		var storeSetErrInjector *fakestoreadapter.FakeStoreAdapterErrorInjector

		JustBeforeEach(func() {
			store.SyncDesiredState(app.DesiredState(1))
			pendingMessage = models.NewPendingStartMessage(time.Unix(100, 0), 30, keepAliveTime, app.AppGuid, app.AppVersion, 0, 1.0, models.PendingStartMessageReasonInvalid)
			pendingMessage.SentOn = sentOn
			store.SavePendingStartMessages(
				pendingMessage,
			)
			storeAdapter.SetErrInjector = storeSetErrInjector
			err = sender.Send()
		})

		BeforeEach(func() {
			keepAliveTime = 0