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<div class="moz-cite-prefix">The phenomenon is called "lava flow",
and is a classic anti-pattern illustrated at
<a class="moz-txt-link-freetext" href="http://antipatterns.com/lavaflow.htm">http://antipatterns.com/lavaflow.htm</a><br>
Their approach to fixing is ancient, though: there are
correctness-preserving refactorings for some of the problem space.
<br>
<br>
Alas, I don't know if middleboxes are correctable... maybe if they
are ones which only care about the IP layer?<br>
<br>
--dave<br>
<br>
On 04/04/18 08:45 AM, Jesper Louis Andersen wrote:<br>
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<blockquote type="cite"
cite="mid:CAGrdgiV-nZ73z1Mr_38eN9YE1xXNEVzduM_jiLBxsD+Od6iP5Q@mail.gmail.com">
<div dir="ltr">On Tue, Apr 3, 2018 at 5:04 PM Jim Gettys <<a
href="mailto:jg@freedesktop.org" moz-do-not-send="true">jg@freedesktop.org</a>>
wrote:<br>
<div class="gmail_quote">
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">To get to
really good RTT's (with low jitter), you still need
fq_codel (or similar). You just can't get there by hacking
TCP no matter how hard you try...
<div dir="ltr">
<div class="gmail_extra">
<div class="gmail_default" style="font-size:small"><br>
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<div class="gmail_quote">I agree with you on all points here.
However, any change which patches an existing bad system is
far more likely to win in the long run, also if it is bad in
some way. Momentum is a killer of good solutions. I wish I had
a ramification for this observation, but I currently don't.<br>
<br>
</div>
<div class="gmail_quote">My hunch is that every new generation
of young programmers wants to put their mark on the system. As
a result, they take what worked well on level N-1 and proceed
to build N on top of it. But the beanstalk never withers, so
each level is present in said stack, still, after all these
years.<br>
<br>
</div>
<div class="gmail_quote">(Aside: The codel approach also has
worked really well for me internally in Erlang systems as a
way to maintain queue load. Far better than many other flow
control schemes).<br>
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<pre class="moz-signature" cols="72">--
David Collier-Brown, | Always do right. This will gratify
System Programmer and Author | some people and astonish the rest
<a class="moz-txt-link-abbreviated" href="mailto:davecb@spamcop.net">davecb@spamcop.net</a> | -- Mark Twain
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