Measuring buyer’s timeout

[ardianp-google]

In PA-API, the seller can specify perBuyerCumulativeTimeouts, but it’s unclear how the buyers can measure:

• How many times they hit the timeout (out of how many auctions)
• How many interest groups manage to submit the bid (and how many interest groups in total).

The above metrics are essential for optimizations. Any suggestions or thoughts to get that number?

I am aware that some of those metrics are sent to the seller (https://github.com/WICG/turtledove/blob/main/FLEDGE_extended_PA_reporting.md#reporting-per-buyer-latency-and-statistics-to-the-seller) via Private Aggregation API, but those metrics (and the denominators) will also be interesting for the buyers.

There’s also a discussion in the same article under “Reporting API informal specification” that touches generateBid() hitting timeout, but it’s not obvious how that handles per-auction metrics instead of per interest-group.

[morlovich]

Hi... So we've been looking to potential ways of addressing feedback given here and in similar issues, and put together a doc with a possible direction:

https://docs.google.com/document/d/1EHVJkKUKIL4dMFrcJ6FJH65Ad4Ml7pKZ8Iepft5OvYk/edit?usp=sharing

we would appreciate feedback on the overall approach, and also on the particularities of metrics and how well they suit their needs (including, of course, potential alternatives you would find preferable). Probably easiest to put it here, since I don't know how to sensibly ACL a public doc so it's accessible to people and not spammers.

[morlovich]

FWIW WICG/turtledove#1272 is the shape it actually seems to be taking in the implementation.

[morlovich]

Just landed experiment config for this for canary/dev 50% (though it will take some time for it to take effect).
Please note that the parsing of new base values is not forward compatible, so you'll want to use try/catch (which you should be using for permission policy anyway).