Push notification architecture for very high volume

Question

Is Apple push notification architecture setup for sending very high volume (dozens of notifications per hour) ? Is this allowed by Apple ? What are the constraints/limits ? Is it reliable ? Are there some delays ? Is there a price to pay for using their service ?

Answer 1

You should read the Local and Push Notification Programming Guide, chapter Apple Push Notification Service.

Answer 2

In order:

1. Yes.
2. Yes.
3. I'm not sure.
4. Mostly; delivery of notifications isn't guaranteed, but the service will attempt to deliver the latest notification your app's generated when a device reappears on the network after being unavailable.
5. Again, there are no particular guarantees, but if the target device is on a good 3G or wifi connection then you can expect the notifications to be delivered within a few seconds of being sent.
6. No. You do, however, need to run your own push notification server (or use a third-party notification-delivery service), which may get costly if you're using a lot of bandwidth and CPU time for your notifications.

For more information, check out the Apple Push Notification Service section in the developer docs.