What is the Concurrent Users Limit for Cloud Firestore Spark Plan?

Solution 1:

Per the Cloud Firestore pricing information (which Firebase uses):

When you use Firestore, you are charged for the following:

• The number of documents you read, write, and delete.
• The amount of storage that your database uses, including overhead for metadata and indexes.
• The amount of network bandwidth that you use.

There is also no mention of any connection limits on Firebase's pricing page or the quotas documentation that you linked.

Unlike the Realtime Database, Cloud Firestore does not charge on a per-connection basis.

This video series also covers the ins and outs of Firebase products and is well worth sitting through.

Think of Cloud Firestore like a folder on your computer, which can contain thousands of little text files, similar to how documents in Cloud Firestore are stored. Users can update them with little chance of collision and grabbing a single document file would only require feeding 1s and 0s back to the requestor. This is why you are charged for network bandwidth rather than by individual connection.

In comparison, the RTDB was similar to one large JSON text file, with many people all trying to update it at once. Because parsing this text file on the server side was required to read and write data from it, it required compute resources to be able to do so. For this reason (among others), the number of connections the RTDB manager processes handled on behalf of spark plans were rate-limited to prevent abuse.