Firebase: Data structuring query - firebase

I am a newbie to firebase and need some suggestions on structuring data.
I am designing a database for an application where multiple people may share a bank account and can update the status of this account. The group of people sharing this account may also keep changing. So, multiple people may perform actions which will influence the balance available in an account. I decided to list the linked accounts under each user so that one pull is enough to get a list of all user accounts once user logs in. If user is interested in details of a specific account (like balance) then I will go and fetch that child from accounts sub-tree. It all seems fine until I think about notifying users in a smartphone app if the balance associated with any of their linked account changes. Since the balance attribute is not under any specific "user" sub-tree, how to monitor for this change at the application level.
I don't want to bring balance attribute under "user" sub-tree or else I will have to find the duplicate copies and update all of them whenever balance of an account changes. Moreover this approach will not scale well.
Any suggestion?

Related

Rate limiting for creating new custom tokens for a user?

My team is using Firebase Auth in our project. We're using custom claims to properly authenticate whether or not a user has access to a specific piece of information. We're storing each piece of information and deciding access for the user based off whether or not the user has access to a specific location. Each piece of data is somehow associated with a location, and we are storing the location id in the custom claims for the ID Token.
The problem is that a user potentially has access to thousands of locations. Instead of storing thousands of locations in the custom claims, we think it's better to generate a new custom token and exchange it for a fresh id token every time the user switches locations. That means that it's potentially reasonable for a user to generate a new custom token every few seconds as they switch through their locations if they are doing it quickly enough.
The Firebase Auth documentation doesn't indicate anything in regards to any rate limiting in this regard.
Are we going to run into any issues / rate limiting if a user switches through their locations very quickly? This would be unusual, but I just want to make sure that the worst case will still work.
The control of Firebase Authentication custom claims is an Admin SDK operation and as such is not subject to rate-limiting. Firebase Authentication as a whole is designed to handle millions of concurrent users and is subject to various rate limits. Updating a user's custom claims would only contribute to the overall limits of 1000ops/sec and 10 million ops/day (at time of writing).
However, custom claims should be used for access control related data that will infrequently change such as the name of a role or a building ID. This is because the propagation of changed custom claims can take up to an hour and requires that the client code manually refresh their tokens after any changes to see an immediate effect. Custom claims have no mechanism to notify clients that they have been updated.
I'd reconsider your approach and store the list of locations a particular user has access to in the Realtime Database or Cloud Firestore rather than the ID token itself. You can then use this information to secure their access using appropriate Security Rules for those databases based on their user ID. By configuring a listener to that portion of the database, your client code can be instantly notified when a user gains or loses access to a new location. Additionally, you can poll information from multiple locations at once so you can show information in a notification feed or dashboard - something that can't be done with the claims strategy.

Firestore security for game where users do not have account

I am confused on the insistence in the documentation to have users sign on to give authentication. With a card game app, I want users to get on easily (without a need to sign on), find a game to play in, and play the game. As cards are played, each turn is recorded in Firestore, and all users notified to read the changed parameters. So all users can read, write and update.
Even if I did make users sign on, anyone could create an account, and I would be no further ahead except I have turned away some game participants.
I know I can set rules so that all data is a small size. I maybe check to ensure no data is stored after a certain time without being used, and I could delete the collection for that game. Is is it this sort of procedures I use to guard the database from growing too big, or a 'bad' user working out where the data is, and overwriting data for some games.
If you want a low-friction way to get users signed in, use anonymous authentication. It will give the user an account with a UID without requiring any prompts. You can then use security rules to protect per-user information, since anonymous accounts have a UID just like normal accounts. You can then decide to let the user upgrade that account when they want a more permanent identity in your game (since anonymous accounts become inaccessible if the user clears their device local storage).

Create firebase project when user log in to SaaS application

I have seen a firebase api in which you can create firebase projects and it occurred to me for example, when a user wants to counter a SaaS, make it easier for me to create a project and connect it to their SaaS but I have the following questions:
If there are supposed to be limits to creating firebase projects in a google account, will there be a time when databases can no longer be created for new users?
If the above is true, how can this be solved?
I have seen that you can ask for more projects, but how many can I have?
I know that with firestore, I can model data and only in a database have all the information, but for example, each user may have special requirements in their system and also provide security and information saving operations that would be impossible if all information is in a single database.
Thanks for the help.
EDIT
"How many projects can you have as a developer?" Yes, that's what I mean, having all the user bases in a single firebase google account. For example, on a web page, the user wants to pay for the application, with firebase admin and google cloud functions, I can automatically create a project and have all the databases in a google account. And what I want to know is if you can have multiple databases. I have seen that you can ask google to give you permission to host several projects but, for example, can you have more than 100 projects or even 1000? (I may never have reached that number, but in that case, I would like to know the limits that can be reached).
Edit 2
This first structure I have all the documents in a "universal" collection and I identify them with an id to know the user who used it.
But the second structure seems to me more organized and clean, in addition to the fact that users at no time need to share information among others. I have read that having nested collections is not good but over the years and the progress that firestore has had, this is no longer or was a problem only that the limitation is that you can only have up to 100 collections anidades but I never think to reach that quantity.
Inside of list, have all products for that user, because inside of document, only can have 1 mb of data and download 1 mb and is not the best option.
in the firestore documentation I see that it does not reveal other problems, it only says that it is difficult to delete the subcollection, but I do not allow users to do that and if I need to delete the subcollections, with the Google Cloud functions i can do it.
So, the second structure is more intuitive for me, but is the best option for that? or actually firestore is not good for this strcucutre?

service granularity

What is the best way to manage domain specific services? For eg: In a Financial domain, Should I have a global service "AccountCreation" or "CheckingAccountCreation", "CreditcardAccountreation" etc.
I am struggling whether to keep them at global level or keep them at the product level. what is the best approach?
You should probably focus in the data first: what data is there, and what data needs to stay consistent. Then focus on what the behaviours around that data are.
In a Financial domain, Should I have a global service "AccountCreation" or "CheckingAccountCreation", "CreditcardAccountreation" etc.
In this example, I would say that you have an "account" service, because you clearly have some accounts - and you probably have to ensure that, eg, you don't duplicate account numbers, apply anti-fraud rules, manage the workflow of creation, etc.
Your examples identify some behaviours: create a checking account, create a credit card account. Those would appropriately be commands that you send to the service, because they result in mutation of the data that the service owns.
If you add a "customer" service, though, that would be distinct from the accounts service: it doesn't have to be consistent with the account service, just to have a reference from accounts to customers by ID.
You also generally don't have shared behaviour that touches both parts - updating data about a customer shouldn't touch the details of their accounts (directly), and updating an account doesn't change the details of a customer.
You might have business rules in one service that change another, such as the account service listening for "a customer became a student" announced by the customer service, and then doing some internal processing.

Allow unregistered customers to place orders in Microsoft Commerce Server 2002

What is the best way of implementing a checkout process that allows customers to place orders without first requiring registration on the site, and without requiring that users create an account during the checkout process.
I was thinking of perhaps creating a anonymous customer entry which all orders not associated with a registered customer get associated with. Will that work?
How would you then recommend accessing order status?
Well the easiest way to do this is to create an account for the user as they checkout. You can generate a password for them to comply with the existing model, and depending on how you want to handle these users you could also flag the record as a "temp" user. You can then remove these users as time expires. These approach gives you the flexibility of also asking the user to create an account after they have successfully checked out; you'd be surprised how many users are willing to just enter a password when thats all they have to do to create an account.
The key here is to make sure you use a unique id for these users as opposed to the email address; otherwise you will run into an issue when the same customer comes over to purchase again within the period where the user still exists.
There are multiple ways of doing "Guest Checkout"; it depends on how much work you want to do upfront and what your long term goals are.

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