I would like to know what is called Message throttling in Google FCM push notification? I am trying to implement a sample push notification using FCM, but didn't understand about message throttling mentioned in their steps. There is no documentation also found about it.
https://aerogear.org/docs/unifiedpush/aerogear-push-android/guides/#google-setup
Could someone clarify about this term?
This documentation of Throttling by https://stuff.mit.edu explains it really well:
To prevent abuse (such as sending a flood of messages to a device) and to optimize for the overall network efficiency and battery life of devices, GCM implements throttling of messages using a token bucket scheme. Messages are throttled on a per application and per collapse key basis (including non-collapsible messages). Each application collapse key is granted some initial tokens, and new tokens are granted periodically therefter. Each token is valid for a single message sent to the device. If an application collapse key exhausts its supply of available tokens, new messages are buffered in a pending queue until new tokens become available at the time of the periodic grant. Thus throttling in between periodic grant intervals may add to the latency of message delivery for an application collapse key that sends a large number of messages within a short period of time. Messages in the pending queue of an application collapse key may be delivered before the time of the next periodic grant, if they are piggybacked with messages belonging to a non-throttled category by GCM for network and battery efficiency reasons.
On a simpler note, I guess you can simply see throttling like a funnel that prevents an overflow of messages (normally for downstream messaging), regulating the in-flow of messages to avoid flooding.
For example, you send 1000 messages to a single device (let's also say that all is sent successfully), there's a chance that GCM will throttle your messages so that only a few would actually push through OR each message will be delivered but not simultaneously to the device.
