Hey Ben! Thanks for working on this! This seems like an important dimension to potentially split metrics on.
On Thu, May 19, 2022 at 10:36 PM 'Ben Mathwig' via blink-dev < blink-dev@chromium.org> wrote: > Contact emails > > bemat...@microsoft.com > > > Explainer > > > https://github.com/MicrosoftEdge/MSEdgeExplainers/blob/main/PerformanceNavigationTiming%20for%20User%20Agent%20Launch/explainer.md > > > Specification > > > https://github.com/MicrosoftEdge/MSEdgeExplainers/blob/main/PerformanceNavigationTiming%20for%20User%20Agent%20Launch/explainer.md > > > Summary > > Adds a new value for PerformanceNavigationTiming.type, 'useragent_launch', > to help measure the cold start scenario during page load. This allows a web > developer to measure the performance of their application code compared to > the cost of browser initialization tasks. This is a pain point for pinned > PWAs or WebView apps that will often require a cold start of the user agent. > > > > > Blink component > > Blink>PerformanceAPIs>NavigationTiming > <https://bugs.chromium.org/p/chromium/issues/list?q=component:Blink%3EPerformanceAPIs%3ENavigationTiming> > > > Motivation > > Despite the variety of performance measurements available through the > current API, it's difficult to discern from the NavigationType whether the > measurements reflect those of a regular navigation under normal browsing or > of one where the browser is in a non-optimal performance state, such as a > cold start. A browser launch is one of the most expensive performance > scenarios commonly encountered in typical PWA and WebView patterns. Our > proposal seeks to create a new value for the NavigationType enum to > differentiate this condition from others in measurements of web application > performance. Modifying the NavigationType to include state for a user agent > launch (i.e. useragent_launch) will enable engineers to determine whether a > given measurement is taken from a launch scenario, enabling greater > differentiation of application performance from browser performance in > scenarios where the browser engine is launched and terminated frequently. > Examples include: Electron apps, system WebViews, or other application > scenarios where the browser is relatively short-lived or commonly launched > from a terminated state. > > > > > Initial public proposal > > > https://discourse.wicg.io/t/proposal-user-agent-launch-type-in-performancenavigationtiming/5875 > Might be worthwhile to also file an issue on https://github.com/w3c/navigation-timing/issues With my WebPerfWG chair hat on, I'd love to have you over to discuss this :) > > > TAG review > > > > > TAG review status > > Pending > > > Risks > > > > > Interoperability and Compatibility > > > > *Gecko*: No signal > > *WebKit*: No signal > > *Web developers*: No signals > > *Other signals*: > > > WebView application risks > > *Does this intent deprecate or change behavior of existing APIs, such that > it has potentially high risk for Android WebView-based applications?* > > > > > Debuggability > > > > > Is this feature fully tested by web-platform-tests > <https://chromium.googlesource.com/chromium/src/+/main/docs/testing/web_platform_tests.md> > ? > > No > > > Flag name > > MsUserAgentLaunchNavType > > > Requires code in //chrome? > > False > > > Estimated milestones > > M105 > > > > > Link to entry on the Chrome Platform Status > > https://chromestatus.com/feature/5186950448283648 > > -- > 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/DM6PR00MB0751A324F65AAAAD9544C2028ED09%40DM6PR00MB0751.namprd00.prod.outlook.com > <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/DM6PR00MB0751A324F65AAAAD9544C2028ED09%40DM6PR00MB0751.namprd00.prod.outlook.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/CAL5BFfV%3D1CMTKmA%3DaOyYfbJVrdY0quT8-zPB1eqRpygMLe%3DidQ%40mail.gmail.com.
