Limitations for Firebase Notification Topics

Question

I want to use Firebase notification for my android application and what i want to know is that is there any limitation for number of topics ? or for the number of users that can subscribe a topic ? For example can i have 10000 topics with 1 million users for each of them ?

Solution 1

There is no limitation on the number of topics or subscriptions. There was a limitation of 1 million subscriptions for the first year after topics was initially launched but that restriction was removed at this year's (2016) Google I/O. FCM now supports unlimited topics and subscribers per app. See the docs for confirmation.

Solution 2

Topic messaging supports unlimited subscriptions for each topic. However, FCM enforces limits in these areas:

1. One app instance can be subscribed to no more than 2000 topics.

2. If you are using batch import to subscribe app instances, each request is limited to 1000 app instances.

3. The frequency of new subscriptions is rate-limited per project. If you send too many subscription requests in a short period of time, FCM servers will respond with a 429 RESOURCE_EXHAUSTED ("quota exceeded") response. Retry with exponential backoff.

Check this https://firebase.google.com/docs/cloud-messaging/android/topic-messaging

Comments

[cafedeichi]

I'd like to know what "app instance" in this official docs means. Does it indicates an app such as an iOS App in a Firebase Project. Or an installed app in a smartphone device?

[REMITH]

Its a good question. As per the Firebase document, "Instance IDs identify individual installations of your app". From this we have to come to conclusion as "app instance" = An installed app in a smartphone device.

[cafedeichi]

@REMITH Thx a lot. I finally understood that.