Firestore has always had a soft limit of 1 write per second to a single document. That meant that for doing things like a counter that updates more frequently than once per second, the recommended solution was sharded counters.

Looking at the Firestore Limits documentation, this limit appears to have disappeared. The Firebase summit presentation mentioned that Firestore is now more scalable, but only mentioned hard limits being removed.

Can anyone confirm whether this limit has indeed been removed, and we can remove all our sharded counters in favor of writing to a single count document tens or hundreds of times per second?

CodePudding user response：

firebaser here

This was indeed removed from the documentation. It was always a soft limit that was not enforced in the code, but instead an estimate for the physical limitation of how long it takes to synchronize the changes to indexes and multiple data center.

We've significantly improved the infrastructure used for these write operations, and now provide tools such a the key visualizer to better analyze performance and look for hot spots in the read and write behavior of your app. While there's still some physical limit, we recommend using these tools rather than depending on a single documented value to analyze your app's database performance.

For most use-cases I'd recommend using the new COUNT() operator nowadays. But if you want to continue using write-time aggregation counters, it is still recommended to use a sharded counter for high-volume count operations, we've just stopped giving a hard number for when to use it.