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?
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:
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
- "Get 10% discount today" (sent on a Monday)
- "Our shop got new site, check it out and get 5% discount" (sent on a
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"
1. This is not how push notifications are used for mobile apps. Push is
to signal, not carry actual (sensitive) data around.
2. 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
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
-  https://github.com/aerogear/aerogear-unifiedpush-server/pull/478
-  https://issues.jboss.org/browse/AGPUSH-971
-  JIRA TO CREATE: to only store ALERT and not the full payload
-  JIRA TO CREATE: update doc regarding push message storage and best