earlier this week there was some discussion about storing the payload of the push notifications ().
Right now, we store some metrics (e.g. client that send the push, number of devices, deliveryStatus etc) and the entire content of push notification. This includes custom key/value pairs, the name of the sound file or even the size of the badge.
Is all of that, storing the entire push notification payload really needed? No!
What do we need, and why?
For counting the number of sent pushes (over time), the metrics are good enough. We do NOT need any of the push content for that, that's correct!
But we want to do more on the 1.1.0 release. We want to introduce some analytic features, to give our app developers (our users) a better understanding of their push usage (see ).
In order to see details on how successful a push was (or not), we need to only store the value of the alert key: https://aerogear.org/docs/unifiedpush/aerogear-push-ios/img/PushMessage.png
Ok, let's change that (see )!
For our app developers, using the UPS to reach out to their mobile app users ("user engagement"), it's important to understand which push was more successful:
- "Get 10% discount today" (sent on a Monday)
- "Our shop got new site, check it out and get 5% discount" (sent on a Friday)
With the upcoming analytics we can help them to improve usage of their app. User interaction is very important to a successful mobile application and push is a key driver here! Our app developers want an app that is actively used by their users (Nobody wants his app sitting on the last page of the device or, even worse, in a folder together with Apple-Maps). Therefore it's critical for our app developers to understand the relevance of their push messages sent and how it impacts the usage of their app. That's why we do the analytics described in . And, yes - only the alert, not the entire payload is needed for that.
On the mentioned PR there was also some discussion about privacy violations and stuff, when we store the content of the notification. An example where sensitive data was sent over push was given. Something like: "Dear Mr. Joe, your blood donation appointment was scheduled for 3 p.m"
- This is not how push notifications are used for mobile apps. Push is to signal, not carry actual (sensitive) data around.
- In a lot of countries, at least almost all European countries, you are not even allowed, by EU law, to give "data" to 3rd party providers (like the push-networks of Microsoft, Apple or Google).
How does the actual (sensitive) data come to an app?
As said above a push is used to signal/ping an app, to indicate that there is real data for the mobile app user. In the background the mobile app tries to connect to the backend of the company, running/maintaining the mobile app. After the real data was fetched, "local notifcations" are used to give the user a visible notification, like "Dear Mr. Joe, your blood donation appointment was scheduled for 3 p.m", or simply "New appointment scheduled".
If the app was a chat system (and not a blood donation app from the Red Cross), it would be the same: After a signal, the app connects to "chat server" and receives the actual chat message from there. A reply would go over the same "chat server" connection. None of this would go over a 3rd party push network provider like Google, Microsoft or Apple.
What would we store from these silent notifications?
Nothing, since there is no alert, we would just store the metrics (e.g. client that send the push, number of devices, deliveryStatus etc). If the signaling is actually done with an alert (e.g. alert:"you got a new Chat text" or "New appointment scheduled"), we would store that.
I hope this helps a bit to understand what is stored and also why we do need a little bit of information.
BTW. our documentation already says that push is used for signaling, not carrying actual data around, but based on this email I will update it to have explicit information on best practices. Also, the documentation will be clear about what (the alert only) is stored by the UPS, and why. (see )