> Apple has billions/trillions of iMessages/Push Notifications going through iCloud and how often have they failed ? Rarely.
Well, there was that 2+ year problem with sending messages to people who'd switched away from iOS (has the fix been released yet?). I'm sure most enterprise customers would consider that a serious failure.
So when you say rarely, I say: Compared to what? As a proportion of total message volume? Perhaps, but I don't think that's the right benchmark.
Compared to similar services from other companies selling to enterprises? That's a much higher bar. And one Apple will have trouble with (contrast the reliability of iMessage and SMS, for example).
> sending messages to people who'd switched away from iOS
For all intents and purposes "switching away from iOS" without signing off of iMessage on the device is equivalent to accidentally going off the grid. iMessage having a (IIRC) two week retention period, it'll bail out after that time. The only way Apple has to distingish between those cases is:
1. have you tell it to Apple and sign out of iMessage on the device (and its associated number on all other devices where said number is referenced)
2. use a timeout with a sensible value to delist the device (you would not want to be delisted after a too short delay, else loss of messages would make for interesting rants)
It's not quite a simple as that. Firstly Apple never ask if you want to use iMessage. If you get an iphone and try sending a SMS it routes it to iMessage automatically without asking. I guess you can turn that off - I don't know how.
Secondly if you switch your iphone for an Android and other iphone users try to send you iMessages, Apple could easily get back to them saying something like "We've been unable to deliver that message to the iphone that used to be there - would you like to try SMS?" but they don't. The fact this doesn't work in spite of people complaining for years suggests they may have deliberately not bothered as it discourages people switching.
That's a fair enough point — except that there's no workaround, even when it ought to be easy to provide one. It's tricky as hell to convince the iPhone to start an SMS conversation with a number that's been flagged as iMessage-enabled. Even if you receive an SMS from that number, and force-send SMSes, it still won't allow you to default to SMS for that conversation.
Well, there was that 2+ year problem with sending messages to people who'd switched away from iOS (has the fix been released yet?). I'm sure most enterprise customers would consider that a serious failure.
And there happens to have been a small iCloud Mail outage this week: http://www.macrumors.com/2014/07/14/icloud-mail-outage/
So when you say rarely, I say: Compared to what? As a proportion of total message volume? Perhaps, but I don't think that's the right benchmark.
Compared to similar services from other companies selling to enterprises? That's a much higher bar. And one Apple will have trouble with (contrast the reliability of iMessage and SMS, for example).