Bugzilla

(In reply to Tim Smith 👨‍🔬 [:tdsmith] from comment #11)
> Thanks for the examples; that's really helpful. This addresses message targeting, right? And enrollment targeting and telemetry is handled by ExperimentManager?

Exactly, this ping only cares about the message targeting. The enrollment targeting and telemetry are indeed handled by ExperimentManager, whih, in turn, relies on Normandy. I've added this bit in the patch.

> 
> The two branches here seem to have identical targeting and trigger expressions; is it the case that all clients would send a reach event containing both branch names when the CFR is displayed? That would be great.

Indeed, their targeting are exactly the same. Since we wanted to run this as an A/A test for ExperimentManager. 

> 
> I'm concerned that there's an [80 character limit](https://firefox-source-docs.mozilla.org/toolkit/components/telemetry/collection/events.html#events-serializationformat) on event values; firing a separate event for each branch instead of concatenating branch names would avoid the risk of failing to send telemetry for complex experiments with many branches, and also has better query ergonomics for the use cases I have in mind.

Yeah, we're aware of those length limitations of Events telemetry, and understanding the risk of string truncation. Will finalize the strategy with Su for a more robust solution. Thanks for the reminder!

(In reply to Tim Smith 👨‍🔬 [:tdsmith] from comment #11)
> Thanks for the examples; that's really helpful. This addresses message targeting, right? And enrollment targeting and telemetry is handled by ExperimentManager?

Exactly, this ping only cares about the message targeting. The enrollment targeting and telemetry are indeed handled by ExperimentManager, which, in turn, relies on Normandy. I've added this bit in the patch.

> 
> The two branches here seem to have identical targeting and trigger expressions; is it the case that all clients would send a reach event containing both branch names when the CFR is displayed? That would be great.

Indeed, their targeting are exactly the same. Since we wanted to run this as an A/A test for ExperimentManager. 

> 
> I'm concerned that there's an [80 character limit](https://firefox-source-docs.mozilla.org/toolkit/components/telemetry/collection/events.html#events-serializationformat) on event values; firing a separate event for each branch instead of concatenating branch names would avoid the risk of failing to send telemetry for complex experiments with many branches, and also has better query ergonomics for the use cases I have in mind.

Yeah, we're aware of those length limitations of Events telemetry, and understanding the risk of string truncation. Will finalize the strategy with Su for a more robust solution. Thanks for the reminder!