Submitting custom pings¶
TelemetryController.submitExternalPing(type, payload, options)
stringthat is the type of the ping, limited to
payload- the actual payload data for the ping, has to be a JSON style object.
options- optional, an object containing additional options:
addClientId- whether to add the client id to the ping, defaults to
addEnvironment- whether to add the environment data to the ping, defaults to
overrideEnvironment- a JSON style object that overrides the environment data
TelemetryController will assemble a ping with the passed payload and the specified options.
That ping will be archived locally for use with Shield and inspection in
If the preferences allow upload of Telemetry pings, the ping will be uploaded at the next opportunity (this is subject to throttling, retry-on-failure, etc.).
Every new data collection in Firefox needs a data collection review from a data collection peer. Just set the feedback? flag for :bsmedberg or one of the other data peers. We try to reply within a business day.
When submitting pings on shutdown, they should not be submitted after Telemetry shutdown. Pings should be submitted at the latest within:
There are other constraints that can lead to a ping submission getting dropped:
- invalid ping type strings
- invalid payload types: E.g. strings instead of objects.
- oversized payloads: We currently only drop pings >1MB, but targetting sizes of <=10KB is recommended.
Helpful tools for designing new pings include:
- gzipServer - a Python script that can run locally and receives and saves Telemetry pings. Making Firefox send to it allows inspecting outgoing pings easily.
about:telemetry- allows inspecting submitted pings from the local archive, including all custom ones.
Designing custom pings¶
In general, creating a new custom ping means you don’t benefit automatically from the existing tooling. Further work is needed to make data show up in re:dash or other analysis tools.
In addition to the data collection review, questions to guide a new pings design are:
- Submission interval & triggers:
- What events trigger ping submission?
- What interval is the ping submitted in?
- Is there a throttling mechanism?
- What is the desired latency? (submitting “at least daily” still leads to certain latency tails)
- Are pings submitted on a clock schedule? Or based on “time since session start”, “time since last ping” etc.? (I.e. will we get sharp spikes in submission volume?)
- Size and volume:
- What’s the size of the submitted payload?
- What’s the full ping size including metadata in the pipeline?
- What’s the target population?
- What’s the overall estimated volume?
- Is it opt-out?
- Does it need to be opt-out?
- Does it need to be in a separate ping? (why can’t the data live in probes?)
- Is there risk to leak PII?
- How is that risk mitigated?
- Data contents:
- Does the submitted data answer the posed product questions?
- Does the shape of the data allow to answer the questions efficiently?
- Is the data limited to whats needed to answer the questions?
- Does the data use common formats? (i.e. can we re-use tooling or analysis know-how)