Telemetry

For clients that have "send anonymous usage data" enabled, Firefox Reality sends a "core" ping and an "event" ping to Mozilla's telemetry service. Sending telemetry can be disabled in the app's settings. Builds of Firefox Reality have telemetry enabled by default ("opt-out").

Core ping

Firefox Reality creates and tries to send a "core" ping whenever the app is started or goes to the background. This core ping uses the same format as Firefox for Android and is documented on firefox-source-docs.mozilla.org.

Recorded searches

Event	location	identifier
Record Search	actionbar	search engine

Event ping

In addition to the core ping an event ping for UI telemetry is generated and sent as soon as the app is sent to the background.

Session

Event	category	method	object	value
Start session (App is in the foreground)	action	foreground	app
Stop session (App is in the background)	action	background	app

Browsing

Event	category	method	object	value	extras
URL entered	action	type_url	search_bar
Search entered	action	type_query	search_bar	bundled engine name

Page Load Time Histogram

Event	category	method	object	extras
Histogram for Page Load Times for Foreground Session	histogram	foreground	browser	histogram*

(*) There are 200 extras attached to this event, each a bucket of 100 ms each, with the key as the minimum value in the bucket and the value as the corresponding number of events in the bucket. Anything over 20,000 is put in the last bucket. For example:

{”0":"2"}
{“100”:"3"}
...
{"19900", "4"}

Time spent in Immersive mode

Event	category	method	object	extras
Histogram for Times spent in Immersive Mode	histogram	immersive_mode	browser	histogram*

(*) There are 200 extras attached to this event, each a bucket of 10000 ms each, with the key as the minimum value in the bucket and the value as the corresponding number of events in the bucket. Anything over 200,000 is put in the last bucket. For example:

{”0":"2"}
{“100”:"3"}
...
{"199000", "4"}

URI Count

Event	Category	Method	Object	Extra
The count of the total non-unique http(s) URIs visited in a subsession, including page reloads, after the session has been restored. This does not include background page requests and URIs from embedded pages or private browsing	action	open	browser	total_uri_count
The count of the unique domains visited in a subsession, after the session has been restored. Subdomains under eTLD are aggregated after the first level (i.e. test.example.com and other.example.com are only counted once). This does not include background page requests and domains from embedded pages or private browsing.	action	open	browser	unique_domains_count

Voice

Event	Category	Method	Object	value	Extra
Search used voice input	action	voice_query	voice_input	bundled engine name

Multi-window

Event	Category	Method	Object	Extra
How long is a window open for	histogram	window_lifetime	Window	histogram*
Frequency of window moves per session	action	windows_move_freq	Window	{"windows_moves_count": num }
Frequency of window resizes per session	action	windows_resize_freq	Window	{"windows_resize_count": num }
Time spent in active window position, per session	action	place_active_time	Window	{"left_window_active_time": num, "front_window_active_time": num, "right_window_active_time": num }
How long are one, two or three windows open, per session	action	open_windows_time	Window	{"one_w_open_time": num, "two_w_open_time": num, "three_w_open_time": num }
How many windows are open at a time, per session	action	windows_open_w	Window	{"one_w_open": num, "two_w_open": num, "three_w_open": num, "one_pri_w_open": num, "two_pri_w_open": num, "thr_pri_w_open": num}

(*) There are 200 extras attached to this event, each a bucket of 1000 ms each, with the key as the minimum value in the bucket and the value as the corresponding number of events in the bucket. Anything over 200,000 is put in the last bucket.

Telemetry Status

This ping is the first ping to be sent when the user enables the Telemetry and the last one when the user disables it.

Event	Category	Method	Object		Extra
Current status of the telemetry	action	telemetry_status	App		{"telemetry_status": boolean }

Limits

No limits are set to the number of pings we send.

New Telemetry System - Glean

Firefox Reality is using Glean component to replace the existing system. Pings are defined by the Glean component and documented in the Glean repository. The list of metrics being collected is available in the metrics. The data is reviewed at this link.

Firefox Reality uses components from Mozilla Android Components. Some of them are using Glean as the tool to do data collection.

• Sync Storage - A syncable implementation of concept-storage and documented in storage-sync. The list of metrics being collected is available in the metrics. The data is reviewed at this link.
• Firefox accounts - A library for integrating with Firefox Accounts and documented in firefox-accounts. The list of metrics being collected is available in the metrics. The data is reviewed at this link.