So, I'm making multiplayer mobile game using Xamarin and Firebase. In game there are many moment when I'm letting players decide what to do and send their decision to the server (by putting decision enum in player-specific Firebase database node). Decision is time limited (short time, no longer than 20s).
I set listener to that specific node in my Firebase functions to check if all player decided or player decision comes after time deadline, but I need to deal with case when: some players send their decision in time - sersnmart were will not execute next action, and that one player just will not send his decision (eave game or something) - server won't be poke again to check deadline and invoke functions.
That why I'm looking for something else, I found method for schedule functions using crontab, but the minimal time interval there seems to be minutes, which is way more to long for me.
Second idea includes wait that specific time interval in previous Firebase thread, but it seems too bad way to deal with this.
Which way is best for dynamic invoking short-interval scheduled Firebase functions?
The best way to schedule Cloud Functions to run at a specific time it through the Google Cloud Tasks schedules. See Doug's blog post for a full description of this: How to schedule a Cloud Function to run in the future with Cloud Tasks (to build a Firestore document TTL)
That said, I regularly use setTimeOut in my own Cloud Functions too when I need to delay an operation for a short period of time. Just keep in mind that you pay for the seconds that the function is sleeping, so cost-wise you'll want to trade that time off against what another invocation would cost.
So for now I decided to use setTimeout, free firebase plan seems to limit only functions invoke number, not working plan so this shouldn't be a problem. Depsite this, I'm still waiting for advice from you
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My application needs front-end searching. It searches an external API, for which I'm limited to a few calls per second.
So, I wanted to keep ALL queries, related to this external API, on the same Cloud Task queue, so I could guarantee the amount of calls per second.
That means the user would have to wait for second or two, most likely, when searching.
However, using Google's const { CloudTasksClient } = require('#google-cloud/tasks') library, I can create a task but when I go to check it's status using .getTask() it says:
The task no longer exists, though a task with this name existed recently.
Is there any way to poll a task until it's complete and retrieve response data? Or any other recommended methods for this? Thanks in advance.
No. GCP Cloud Tasks provides no way to gather information on the body of requests that successfully completed.
(Which is a shame, because it seems quite natural. I just wrote an email to my own GCP account rep asking about this possible feature. If I get an update I'll put it here.)
I need to run a function in firebase every 10 seconds (I call an external api and process data).
With a normal cron I cant because it is limited to maximum once a minute. Using a setTimeOut is also not convenient since Functions charges per second of use.
My only idea so far is to use Cloud Tasks. But I don't know if it is the most convenient to use this tool for my purpose.
On Google Cloud Platform, Cloud Tasks is almost certainly the best/only way to get this job done without using other products in a way that they weren't intended. Cloud Functions is not good for the reasons you mentioned. With Cloud Tasks, you will need to have the prior task schedule the next task upon completion, as they will not repeat themselves automatically like cron.
I need to schedule certain daily tasks, example payment notifications, payments and other things. My question is if through Cloud Functions I can get this.
An example of a task I need, is to make a daily payment, for 8 months, from Monday to Friday.
Activation of this I can do with a Cloud Function and the payment schedule I want to implement node-schedule. The main reason is because I use Cloud Firestore and it comes in handy in the project to implement the functions of the cloud and the database.
That's why I open the post, to know if it is possible for the Cloud Function to load these tasks in memory and execute them when node-schedule requires it.
Thank you.
Cloud Functions have a maximum execution time of 9 minutes, and you are billed for CPU and memory usage the entire time an instance is running. Using an in-process scheduler like node-schedule isn't possible for long time periods and isn't generally recommended even for shorter ones due to the cost involved.
Instead, you can use scheduled functions to define an arbitrary cron-like repeating job that will execute a function on a set schedule. It should be very possible to establish a "Mon-Fri daily payment" in such a scheduled function.
I'm building an app using Firebase. There's an admin setting I want to build, that essentially populates one of my nodes with data. It would do this every 10 minutes, and there are 50-80 data points that I'd want to add.
So this would take roughly 13 hours total, I'd probably want to expand this though in the future. I would only call this function, maybe once a week.
I would simply do this using a setTimeout but I've heard this can be expensive? Does someone know roughly how expensive this would be?
I'm not that experienced with CRON jobs, is there a better way of doing this with Firebase? It's not something I want to have running constantly, and it's not at a specific time, but just whenever I need it. I'd also potentially want to have the job running multiple times, at the same time. Which seems to be super easy using Firebase Functions.
Any ideas? Thank you!
You would have to trigger the functions from an outside source.
One way you could do that is by creating and subscribing to a pub-sub system:
exports.someSubscription = functions.pubsub.topic('some-subscription').onPublish((event) => {
// Your code here
});
Another way you could trigger the functions is by exposing them as http requests and hitting those endpoints - See this amazing article on the firebase documentation for some resources on creating http endpoints.
Both of these ways require you to have some sort of scheduling service to either publish a new event to your subscription or to hit the http endpoint. You will need to either implement these services yourself, however I am sure there are services out there that can do that for you.
Let's say I have a Cloud Firebase Function - called by a cron job - that produces 30+ tasks every time it's invoked.
These tasks are quite slow (5 - 6 second each in average) and I can't process them directly in the original because it would time out.
So, the solution would be invoking another "worker" function, once per task, to complete the tasks independently and write the results in a database. So far I can think of three strategies:
Pubsub messages. That would be amazing, but it seems that you can only listen on pubsub messages from within a Cloud Function, not create one. Resorting to external solutions, like having a GAE instance, is not an option for me.
Call the worker http-triggered Firebase Cloud Function from the first one. That won't work, I think, because I would need to wait for a response from the all the invoked worker functions, after they finish and send, and my original Function would time out.
Append tasks to a real time database list, then have a worker function triggered by each database change. The worker has to delete the task from the queue afterwards. That would probably work, but it feels there are a lot of moving parts for a simple problem. For example, what if the worker throws? Another cron to "clean" the db would be needed etc.
Another solution that comes to mind is firebase-queue, but its README explicitly states:
"There may continue to be specific use-cases for firebase-queue,
however if you're looking for a general purpose, scalable queueing
system for Firebase then it is likely that building on top of Google
Cloud Functions for Firebase is the ideal route"
It's not officially supported and they're practically saying that we should use Functions instead (which is what I'm trying to do). I'm a bit nervous on using in prod a library that might be abandoned tomorrow (if it's not already) and would like to avoid going down that route.
Sending Pub/Sub messages from Cloud Functions
Cloud Functions are run in a fairly standard Node.js environment. Given the breadth of the Node/NPM ecosystem, the amount of things you can do in Cloud Functions is quite broad.
it seems that you can only listen on pubsub messages from within a Cloud Function, not create one
You can publish new messages to Pub/Sub topics from within Cloud Functions using the regular Node.js module for Pub/Sub. See the Cloud Pub/Sub documentation for an example.
Triggering new actions from Cloud Functions through Database writes
This is also a fairly common pattern. I usually have my subprocesses/workers clean up after themselves at the same moment they write their result back to the database. This works fine in my simple scenarios, but your mileage may of course vary.
If you're having a concrete cleanup problem, post the code that reproduces the problem and we can have a look at ways to make it more robust.