Firebase 雲功能非常慢 - Firebase cloud functions is very slow

問題：

We're working on an application that uses the new firebase cloud functions.我們正在開發一個使用新的 firebase 雲功能的應用程序。 What currently is happening is that a transaction is put in the queue node.當前發生的是將事務放入隊列節點。 And then the function removes that node and puts it in the correct node.然後該函數刪除該節點並將其放入正確的節點中。 This has been implemented because of the ability to work offline.由於能夠脫機工作，因此已實施。

Our current problem is the speed of the function.我們當前的問題是函數的速度。 The function itself takes about 400ms, so that's alright.該函數本身大約需要 400 毫秒，所以沒關係。 But sometimes the functions take a very long time (around 8 seconds), while the entry was already added to the queue.但有時函數需要很長時間（大約 8 秒），而條目已經添加到隊列中。

We suspect that the server takes time to boot up, because when we do the action once more after the first.我們懷疑服務器需要時間來啓動，因爲當我們在第一次之後再次執行操作時。 It takes way less time.它需要更少的時間。

Is there any way to fix this problem?有沒有辦法解決這個問題？ Down here i added the code of our function.在這裏，我添加了我們函數的代碼。 We suspect there's nothing wrong with it, but we added it just in case.我們懷疑它沒有任何問題，但我們添加了它以防萬一。

const functions = require('firebase-functions');
const admin = require('firebase-admin');
const database = admin.database();

exports.insertTransaction = functions.database
    .ref('/userPlacePromotionTransactionsQueue/{userKey}/{placeKey}/{promotionKey}/{transactionKey}')
    .onWrite(event => {
        if (event.data.val() == null) return null;

        // get keys
        const userKey = event.params.userKey;
        const placeKey = event.params.placeKey;
        const promotionKey = event.params.promotionKey;
        const transactionKey = event.params.transactionKey;

        // init update object
        const data = {};

        // get the transaction
        const transaction = event.data.val();

        // transfer transaction
        saveTransaction(data, transaction, userKey, placeKey, promotionKey, transactionKey);
        // remove from queue
        data[`/userPlacePromotionTransactionsQueue/${userKey}/${placeKey}/${promotionKey}/${transactionKey}`] = null;

        // fetch promotion
        database.ref(`promotions/${promotionKey}`).once('value', (snapshot) => {
            // Check if the promotion exists.
            if (!snapshot.exists()) {
                return null;
            }

            const promotion = snapshot.val();

            // fetch the current stamp count
            database.ref(`userPromotionStampCount/${userKey}/${promotionKey}`).once('value', (snapshot) => {
                let currentStampCount = 0;
                if (snapshot.exists()) currentStampCount = parseInt(snapshot.val());

                data[`userPromotionStampCount/${userKey}/${promotionKey}`] = currentStampCount + transaction.amount;

                // determines if there are new full cards
                const currentFullcards = Math.floor(currentStampCount > 0 ? currentStampCount / promotion.stamps : 0);
                const newStamps = currentStampCount + transaction.amount;
                const newFullcards = Math.floor(newStamps / promotion.stamps);

                if (newFullcards > currentFullcards) {
                    for (let i = 0; i < (newFullcards - currentFullcards); i++) {
                        const cardTransaction = {
                            action: "pending",
                            promotion_id: promotionKey,
                            user_id: userKey,
                            amount: 0,
                            type: "stamp",
                            date: transaction.date,
                            is_reversed: false
                        };

                        saveTransaction(data, cardTransaction, userKey, placeKey, promotionKey);

                        const completedPromotion = {
                            promotion_id: promotionKey,
                            user_id: userKey,
                            has_used: false,
                            date: admin.database.ServerValue.TIMESTAMP
                        };

                        const promotionPushKey = database
                            .ref()
                            .child(`userPlaceCompletedPromotions/${userKey}/${placeKey}`)
                            .push()
                            .key;

                        data[`userPlaceCompletedPromotions/${userKey}/${placeKey}/${promotionPushKey}`] = completedPromotion;
                        data[`userCompletedPromotions/${userKey}/${promotionPushKey}`] = completedPromotion;
                    }
                }

                return database.ref().update(data);
            }, (error) => {
                // Log to the console if an error happened.
                console.log('The read failed: ' + error.code);
                return null;
            });

        }, (error) => {
            // Log to the console if an error happened.
            console.log('The read failed: ' + error.code);
            return null;
        });
    });

function saveTransaction(data, transaction, userKey, placeKey, promotionKey, transactionKey) {
    if (!transactionKey) {
        transactionKey = database.ref('transactions').push().key;
    }

    data[`transactions/${transactionKey}`] = transaction;
    data[`placeTransactions/${placeKey}/${transactionKey}`] = transaction;
    data[`userPlacePromotionTransactions/${userKey}/${placeKey}/${promotionKey}/${transactionKey}`] = transaction;
}

---

解決方案：

參考一： https://en.stackoom.com/question/2tHD4
參考二： https://stackoom.com/question/2tHD4