Firebase cloud function taking over 5 minutes to update database

Question

The console shows that the function has been executed in 2 - 3 seconds. But it takes around 5 minutes to update in database. Is it normal for cloud functions to take so long to propagate changes? Is there any way the delay can be reduced to a few seconds?

Below is the code for cloud function. I trigger it with a url visit. (I know the code smells, but this is a prototype only).

    const listID = req.query.id;
    const user = req.query.user;
    const code = req.query.code;
    const title = req.query.title;
    const desc = req.query.desc;

    var docRef = admin.firestore().collection('users/' + user.toString() + '/wordLists/' + listID.toString() + '/words');
    var docRef2 = admin.firestore().doc("users/" + user.toString() + "/wordLists/" + listID.toString());
    var docRef3 = admin.firestore().doc("users/" + user.toString());    //new 

    var description, length, name, courseId;
    
    description = desc;
    name = title;
    console.log("Description: " + description + ", d: " + desc);

    docRef2.get().then(
        function(doc) {
            if (doc.exists) {
                length = doc.data().length;
                courseId = user.toString()+","+listID.toString()+"," + code.toString();
                admin.firestore().collection('courses').doc(courseId).set({
                    description: description,
                    id: courseId,
                    length: length,
                    name: name,
                    creator: user,
                    downloads: 0,
                    rating: 0,
                    published: true,
                });
                
            } else {
                console.log("FAILED users/" + user.toString() + "/wordLists/" + listID.toString());
            }
            return "Done";
    }).catch(function(error) {
        console.log("Error getting document:", error);
    });

    docRef.get().then(function(querySnapshot){
        querySnapshot.forEach(function(doc) {
        if (doc.exists) {
            var mid = doc.data().meaningID;
            var smi = doc.data().subMeaningIndex;
            var docId = mid.toString() + "," + smi.toString();

            
            admin.firestore().collection('courses/'+ courseId + '/words').doc(docId).set({
                examples: doc.data().examples,
                meaningID: mid,
                subMeaning: doc.data().subMeaning,
                subMeaningIndex: smi,
                word: doc.data().word,
            });
        } else {
            console.log('users/' + user.toString() + '/wordLists/' + listID.toString() + '/words');
        }
        //return "Done";
    });
    return "Done2";
    }).catch(function(error) {
        console.log("Error getting document:", error);
    });
    
    docRef3.get().then(
        function(doc) {
            if (doc.exists) {
                var l = doc.data().coursesCreated;
                l.push(courseId);
                docRef3.update({coursesCreated: l});
            } else {
                console.log("users/" + user.toString() + "/wordLists/" + listID.toString());
            }
            return "Done";
    }).catch(function(error) {
        console.log("Error getting document:", error);
    });
    
    res.send("Success");

Here is the console output. You can see that the console.log output from 4:26 comes after they say the function execution finished. : Console output log

Answer 1

In your code, since you execute Promise-based non-blocking functions, the res.send() part is immediately accessed. As Doug writes, you should put it inside a Promise callback.

You should either send a res.send() within a .then() block or a res.status(500).send() within a .catch() block and only once.

You could also use async/await (within a try/catch structure) if you don't want to deal with Promises cascading.