Increasing the limit on interest group size?

[jonasz]

Hi,

Currently there is a limit of 50kB on the size of a single interest group. We are considering, for various reasons, adjusting our system to only create a single IG per advertiser. By doing so we'd need to squeeze in more information in a single IG instance, and the 50kB limit becomes problematic.

I was wondering, would it be possible to increase the limit? Or perhaps to introduce a single limit for the total size of all interet groups created on a specific domain by a specific owner, and drop the per-IG 50kB limit?

Best regards,
Jonasz

[stguav]

We are also interested in this direction, depending on how some of the issues mentioned in #361 get addressed.

[dmdabbs]

I didn't find a 50kB limit. Would you mind referring me to it? TY

[jonasz]

Hi David, you can find it here https://wicg.github.io/turtledove/spec.html#joining-interest-groups if you search for "50 KB".

[dmdabbs]

Thank you @jonasz. If the proposed sellerCapabilities (née approvedSellers) field for granting per-buyer latency/stats reporting permission is added to the 'budget' we will need even more headroom. Surely there is another more flexible means for buyers to grant these perms that does not burden every addInterestGroup registration.

[caraitto]

I think we can consider something like @jonasz proposed -- a per joining origin / site limit across all interest groups joined from that origin / site. We'd still need a global limit, since the number of origins / sites that a user can visit is arbitrarily large.

What new limit values would work for you?

[jonasz]

What do you think about 5MB per (owner, site), and 50MB per (owner)? These should be comfortable limits for us judging by our current usage and estimates.

[gianni-99]

That could work for us too. We would like to revisit the numbers once we get more FLEDGE traffic.

[brusshamilton]

We're looking into increasing the per-interest group limit to 1MB, with a limit of 10MB per owner. Does that sound like it would be sufficient for your use cases?
The size of interest groups plays a role in auction latency since they need to be read from disk, deserialized, sent across processes, and loaded into v8. All of these delays increase with the size of the interest group, and the disk read and deserialization need to happen even if the interest group doesn't bid.

[brusshamilton]

Circling back to this, we increased the per-interest group size limit to 1MB, with a limit of 10MB per owner. That change rolled out in Chrome release M114.

[davideanastasia]

If a publishers is hosting -- for instance -- 10 interest group owners, would that equate to process 100Mb of data for each runAdAuction in the worst case scenario?
If that's the case -- please correct me if I am on the wrong track -- that could easily lead to extreme high CPU usage from the browser.