[Bloat] [Rpm] Airbnb

Matt Mathis mattmathis at google.com
Tue Aug 10 00:51:54 EDT 2021

I am part of the M-Lab team.

For years we published a "jitter" metric that I considered to be bogus,
basically max_rtt - min_rtt, (which were builtin Web100 instruments).

In 2019, we transitioned from web100 to "standard" linux tcp_info, which
does not capture max_rtt.   Since the web100 jitter was viewed as bogus, we
did not attempt to reconstruct it, although we could have.   Designing and
implementing a new latency metric was on my todo list from the beginning of
that transition, but chronically preempted by more pressing problems.

It finally made it to the top of my queue which is why I am suddenly not
lurking here and the new rpm list.  I was very happy to see the Apple
responsiveness metric, and realized that M-Lab can implement a TCP
version of it, that can be computed both in real time on future tests and
retroactively over archived tests collected over the last 12 years.

This quick paper might be of interest: Preliminary Longitudinal Study of
Internet Responsiveness
The best way to predict the future is to create it.  - Alan Kay

We must not tolerate intolerance;
       however our response must be carefully measured:
            too strong would be hypocritical and risks spiraling out of
            too weak risks being mistaken for tacit approval.

On Mon, Aug 9, 2021 at 5:27 PM Dave Collier-Brown <
dave.collier-brown at indexexchange.com> wrote:

> Knowing programmers, I'd more likely assume latency when it's easiest to
> measure. At a guess, either
>    - average of upload or download
>    - average of download (as it comes first)
> --dave (call me "Wally" (:-)) c-b
> On 2021-08-09 4:24 p.m., Jonathan Morton wrote:
> On 9 Aug, 2021, at 10:25 pm, Dave Collier-Brown <dave.collier-brown at indexexchange.com> <dave.collier-brown at indexexchange.com> wrote:
> My run of it reported latency, but without any qualifiers...
> One would reasonable assume that's idle latency, then.
>  - Jonathan Morton
> _______________________________________________
> Bloat mailing listBloat at lists.bufferbloat.nethttps://lists.bufferbloat.net/listinfo/bloat
> --
> David Collier-Brown,         | Always do right. This will gratify
> System Programmer and Author | some people and astonish the restdave.collier-brown at indexexchange.com |              -- Mark Twain
> including any and all attachments, contains confidential information
> intended only for the person(s) to whom it is addressed. Any dissemination,
> distribution, copying or disclosure is strictly prohibited and is not a
> waiver of confidentiality. If you have received this telecommunication in
> error, please notify the sender immediately by return electronic mail and
> delete the message from your inbox and deleted items folders. This
> telecommunication does not constitute an express or implied agreement to
> conduct transactions by electronic means, nor does it constitute a contract
> offer, a contract amendment or an acceptance of a contract offer. Contract
> terms contained in this telecommunication are subject to legal review and
> the completion of formal documentation and are not binding until same is
> confirmed in writing and has been signed by an authorized signatory.*
> _______________________________________________
> Bloat mailing list
> Bloat at lists.bufferbloat.net
> https://lists.bufferbloat.net/listinfo/bloat
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.bufferbloat.net/pipermail/bloat/attachments/20210809/d64e305d/attachment-0001.html>

More information about the Bloat mailing list