LGTM2 Talking to the team, the 10K limit is Finchable, so we'd be able to lower it if this runs into issues in the field. Also presumably, having that as a limit doesn't mean most responses would actually use that.
On Sat, Sep 16, 2023 at 6:52 AM Yoav Weiss <yoavwe...@chromium.org> wrote: > > > > On Fri, Sep 15, 2023 at 10:00 PM Mike Taylor <miketa...@chromium.org> > wrote: > >> Thanks, LGTM1 pending the PRs landing. >> On 9/12/23 12:29 AM, Caleb Raitto wrote: >> >> Hi Mike, >> >> Pull request 695 <https://github.com/WICG/turtledove/pull/695> is the >> change to update the explainer to describe the new header-based >> directFromSellerSignals, whereas 771 >> <https://github.com/WICG/turtledove/pull/771> and 774 >> <https://github.com/WICG/turtledove/pull/774> are for the spec changes. >> >> The explainer change describes usage of the new API and provides context >> for the differences between header-based and the prior bundles based >> versions of directFromSellerSignals, whereas the spec change describes how >> to implement the header-based version. >> >> We intend to land all 3 pull requests. >> >> Thanks, >> >> -Caleb >> On Monday, September 11, 2023 at 11:18:26 AM UTC-4 Mike Taylor wrote: >> >>> >>> On 9/11/23 12:55 PM, Mike Taylor wrote: >>> >>> On 9/7/23 6:00 PM, Caleb Raitto wrote: >>> >>> Hi Yoav, some responses inline: >>> >>> On Wednesday, September 6, 2023 at 12:15:45 PM UTC-4 Yoav Weiss wrote: >>> >>> On Tue, Sep 5, 2023 at 9:55 PM Paul Jensen <pauljen...@chromium.org> >>> wrote: >>> >>> Contact emails >>> >>> >>> * pauljen...@chromium.org <pauljen...@chromium.org> *Explainer >>> >>> * https://github.com/WICG/turtledove/pull/69 >>> <https://github.com/WICG/turtledove/pull/695>5 * >>> >>> >>> Can you clarify what this does, as the explainer is not very explain-y? >>> >>> IIUC, the current flow to get directFromSellerSignals is to download a >>> response A which contains a link to a WBN, then download the WBN and that >>> contains the signal info. >>> Your proposal is to change that so that the directFromSellerSignals >>> information would be embedded in a response header on response A? >>> >>> >>> The original directFromSellerSignals worked by downloading a response A, >>> from the seller’s origin, that is a WBN containing several subresources >>> that represent signals from the seller to various auction participants -- >>> no linking was involved. >>> >>> > Can you outline that flow more explicitly? Apologies, but I'd like to > better understand its performance characteristics. > IIUC, in both cases we have an initial page that triggers a request, where > in one that request is to a WBN (using a <link> ?) and the other it's to a > random resource using fetch({adAuctionHeaders: true}) ? > > I guess it's unclear to me why the former would be slower than the latter, > especially given the large payloads and the fact that headers can't really > be compressed. > > >>> You’re correct about this header-based version of >>> directFromSellerSignals -- when Chrome downloads a response, from the >>> seller’s origin, with fetch(..., {adAuctionHeaders: true}), the >>> Ad-Auction-Signals header gets parsed as JSON to provide the signals. >>> >>> >>> >>> If so, any more details on that header? What would be the header name? >>> What payload sizes should we expect for the header's value? In what >>> conditions will it actually be processed? >>> >>> >>> The name of the header is Ad-Auction-Signals, as mentioned here in the >>> explainer: [0]. Currently, the payload size is limited to 1kb [1], but >>> we’re considering increasing that to 10kb based on feedback. When Chrome >>> conducts a Protected Audience auction, it processes any received >>> Ad-Auction-Signals headers whose adSlot matches that of the auction. The >>> header contains JSON that dictates which signals are sent to which auction >>> participants. >>> >>> > 1K header is a lot. 10KB header is... really a lot. > Have you tested that with a variety of CDNs and other intermediaries? I > wouldn't be surprised if those values would break some assumptions in > existing HTTP proxying software. > > Also, the JSON y'all are sending doesn't seem extremely nested. Have you > considered structured fields <https://www.rfc-editor.org/rfc/rfc8941.html> > ? > > >> >>> [0] >>> https://github.com/WICG/turtledove/pull/695/files#diff-d65ba9778fe3af46de3edfce2266b5b035192f8869280ec07179963b81f4e624R465 >>> >>> [1] >>> https://source.chromium.org/chromium/chromium/src/+/main:content/browser/interest_group/ad_auction_url_loader_interceptor.cc;l=195;drc=dcd52bb9a48216858a950b919383c44a290273f7 >>> >>> Thanks for the explanation - what's preventing >>> https://github.com/WICG/turtledove/pull/695 from landing? It seems >>> rather old (and references stuff that no longer exists, like >>> `X-FLEDGE-Auction-Only`. (It also doesn't seem to define any error-handling >>> for parsing the JSON that a server returns, which would be good to do.) >>> >>> I maybe have just been confused. I'm not sure if 695 is intended to >>> land, beyond 771 and 774, both of which have much more recent activity. >>> >>> >>> Thanks, >>> >>> -Caleb >>> >>> >>> Specification >>> >>> >>> * https://github.com/WICG/turtledove/pull/771 >>> <https://github.com/WICG/turtledove/pull/771> >>> https://github.com/WICG/turtledove/pull/774 >>> <https://github.com/WICG/turtledove/pull/774> *Summary >>> >>> >>> * Protected Audience already supports a mechanism to ensure the >>> authenticity and integrity of information passed into the auction from the >>> seller called directFromSellerSignals. Currently this is implemented by the >>> seller providing subresources in a WebBundle to the browser, which after a >>> year of testing has proved to not be as efficient as originally planned. It >>> either requires an entirely new additional fetch of a WebBundle, or for the >>> seller to rewrite and rework an existing fetch to respond instead with only >>> a WebBundle. This feature is a rewrite of directFromSellerSignals to use an >>> HTTP response header, transferred via HTTPS same-origin with the seller, >>> instead of a WebBundle to optimize performance. *Blink component >>> >>> >>> * Blink>InterestGroups >>> <https://bugs.chromium.org/p/chromium/issues/list?q=component:Blink%3EInterestGroups> >>> *TAG review >>> >>> >>> * The parent proposal, Protected Audience, is still pending: >>> https://github.com/w3ctag/design-reviews/issues/723 >>> <https://github.com/w3ctag/design-reviews/issues/723> *TAG review status >>> >>> >>> * Pending *Risks >>> >>> Interoperability and Compatibility >>> >>> * None as this is an optional new way of providing >>> directFromSellerSignals. It cannot be used jointly with the old mechanism, >>> but there shouldn’t be a need to use the old mechanism. * >>> >>> >>> * Gecko & WebKit: No signal on parent proposal, Protected Audience. >>> Asked in the Mozilla forum here >>> <https://github.com/mozilla/standards-positions/issues/770>, and in the >>> Webkit forum here >>> <https://github.com/WebKit/standards-positions/issues/158>. * >>> >>> >>> * Web developers: Adtech asked for this via this Protected Audience >>> Github issue >>> <https://github.com/WICG/turtledove/issues/119#issuecomment-1274013176>. * >>> >>> >>> >>> Debuggability >>> >>> >>> * This feature affects values provided to Protected Audience scripts >>> (generateBid(), reportResult(), reportWin()) which are debuggable via >>> Chrome DevTools. This feature also includes console log warnings on parse >>> failures. *Will this feature be supported on all six Blink platforms >>> (Windows, Mac, Linux, Chrome OS, Android, and Android WebView)? >>> >>> >>> * It will be supported on all platforms that support Protected Audience, >>> so all but WebView. *Is this feature fully tested by web-platform-tests >>> <https://chromium.googlesource.com/chromium/src/+/main/docs/testing/web_platform_tests.md> >>> ? >>> >>> >>> * We plan to add WPTs to cover this API in the next month. *Flag name >>> on chrome://flags >>> >>> >>> * None *Finch feature name >>> >>> >>> * FledgeDirectFromSellerSignalsHeaderAdSlot *Requires code in //chrome? >>> >>> >>> * False *Estimated milestones >>> >>> >>> * Shipping on desktop and Android in M117. *Anticipated spec changes >>> >>> >>> * None related to this feature. *Link to entry on the Chrome Platform >>> Status >>> >>> https://chromestatus.com/feature/5165311598264320 >>> >>> This intent message was generated by Chrome Platform Status >>> <https://chromestatus.com/>. >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "blink-dev" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to blink-dev+unsubscr...@chromium.org. >>> To view this discussion on the web visit https://groups.google.com/a/ >>> chromium.org/d/msgid/blink-dev/CABQTWrkbaAuRoxPUtrQnxyS-W%3DfZjba1JN% >>> 2BHCHyLmKCKveHXOg%40mail.gmail.com >>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CABQTWrkbaAuRoxPUtrQnxyS-W%3DfZjba1JN%2BHCHyLmKCKveHXOg%40mail.gmail.com?utm_medium=email&utm_source=footer> >>> . >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "blink-dev" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to blink-dev+unsubscr...@chromium.org. >>> To view this discussion on the web visit >>> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/5c238b79-7120-4089-a8d7-dc1e67f956fcn%40chromium.org >>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/5c238b79-7120-4089-a8d7-dc1e67f956fcn%40chromium.org?utm_medium=email&utm_source=footer> >>> . >>> >>> -- You received this message because you are subscribed to the Google Groups "blink-dev" group. 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