Rules for dropping or pausing interest groups under resource pressure?

[dmarti]

Users in some situations, such as doing a long online shopping session on an underpowered device, may find themselves in a large enough number of FLEDGE interest groups to have a noticeable impact on performance. Will the browser always run all bidding functions from the interestGroupBuyers passed by the seller, even if it impacts performance as seen by the user? (so always the seller's responsibility to limit participants if needed?) Or will the browser drop or pause any interest groups, and if so, how is the order determined?

Related: #46 #215 https://developer.chrome.com/blog/heavy-ad-interventions/

[JensenPaul]

Will the browser always run all bidding functions from the interestGroupBuyers passed by the seller, even if it impacts performance as seen by the user?

The Heavy Ad Interventions take effect at significantly higher limits (e.g. 60 seconds of main thread usage) than the FLEDGE auction's default timeouts (e.g. 50 milliseconds per generateBid() invocation on threads other than the main thread), so I don't think we've given a lot of thought to the how the former might apply to the later.

so always the seller's responsibility to limit participants if needed?

FLEDGE offers several timeout and limit options instead of simply limiting participants. For example:

• sellerTimeout
• perBuyerTimeouts
• perBuyerGroupLimits
• perBuyerCumulativeBiddingTimeouts
• signal which can be used to apply overall auction timeouts.

Or will the browser drop or pause any interest groups

The timeouts and limits above give fine grained control.

how is the order determined?

Buyers can prioritize their interest groups using the priority field, and this can be further adjusted in real-time using a vector of values coming from their trusted bidding signals server which is dot producted with the priorityVector field.

[dmarti]

Thank you -- this is not about the already documented timeouts, but what happens when a site deliberately calls navigator.runAdAuction for a user on an unusually slow or overloaded device who is in an unusually large number of interest groups (as the result of misconfiguration, an extreme shopping session, or both)

Are any protection measures present in the browser to prevent excess battery consumption or jankiness when too many FLEDGE tasks are running?