Re: drop "Resource Error Logging" in favor of failed fetches in Resource Timing?

On Fri, Oct 17, 2014 at 6:13 PM, Ilya Grigorik <igrigorik@google.com> wrote:

> On Fri, Oct 17, 2014 at 12:40 AM, Ben Maurer <ben.maurer@gmail.com> wrote:
>
>> One potential reason to go with the REL approach is that there is always
>> the possibility that the resource containing the actual logging code is the
>> one that failed to load (ie, a failure in your CDN that served javascript).
>>
>
> Note that REL does *not* provide UA-reporting infrastructure - that only
> applies to Nav Error Logging. The assumption is that to fetch a subresource
> you must have successfully loaded the parent page first, and if that's the
> case, then you can ship some error code within it to listen for subresource
> fetches and log their status appropriately - e.g. via Beacon.
>
>

Why not hook into the UA reporting infra provided by NEL? What would the JS
in the parent page do more intelligently than the default UA infra. Failure
in the JS CDN seems like a perfect use case.

Even if there's not UA reporting in REL, at the very least if the JS works
on a subsequent page load, the data will get back to the site.