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    <p>This bit posted by Randy might get lost in the other thread, but
      it appears that their DNS withdraws BGP routes for prefixes that
      they can't reach or are flaky it seems. Apparently that goes for
      the prefixes that the name servers are on too. This caused
      internal outages too as it seems they use their front facing DNS
      just like everybody else. <br>
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    <p>Sounds like they might consider having at least one split horizon
      server internally. Lots of fodder here.</p>
    <p>Mike<br>
    </p>
    <div class="moz-cite-prefix">On 10/5/21 11:11 AM, Randy Monroe
      wrote:<br>
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cite="mid:CALOB-K_e0JxWhsk2RC=AvFdNnzFbbv66xfK0d0bVz7Qw=xuPFA@mail.gmail.com">
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      <div dir="ltr">Updated: <a
href="https://engineering.fb.com/2021/10/05/networking-traffic/outage-details/"
          moz-do-not-send="true">https://engineering.fb.com/2021/10/05/networking-traffic/outage-details/</a></div>
      <br>
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        <div dir="ltr" class="gmail_attr">On Tue, Oct 5, 2021 at 1:26 PM
          Michael Thomas <<a href="mailto:mike@mtcc.com"
            moz-do-not-send="true">mike@mtcc.com</a>> wrote:<br>
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          On 10/5/21 12:17 AM, Carsten Bormann wrote:<br>
          > On 5. Oct 2021, at 07:42, William Herrin <<a
            href="mailto:bill@herrin.us" target="_blank"
            moz-do-not-send="true">bill@herrin.us</a>> wrote:<br>
          >> On Mon, Oct 4, 2021 at 6:15 PM Michael Thomas <<a
            href="mailto:mike@mtcc.com" target="_blank"
            moz-do-not-send="true">mike@mtcc.com</a>> wrote:<br>
          >>> They have a monkey patch subsystem. Lol.<br>
          >> Yes, actually, they do. They use Chef extensively to
          configure<br>
          >> operating systems. Chef is written in Ruby. Ruby has
          something called<br>
          >> Monkey Patches.<br>
          > While Ruby indeed has a chain-saw (read: powerful,
          dangerous, still the tool of choice in certain cases) in its
          toolkit that is generally called “monkey-patching”, I think
          Michael was actually thinking about the “chaos monkey”,<br>
          > <a
            href="https://en.wikipedia.org/wiki/Chaos_engineering#Chaos_Monkey"
            rel="noreferrer" target="_blank" moz-do-not-send="true">https://en.wikipedia.org/wiki/Chaos_engineering#Chaos_Monkey</a><br>
          > <a href="https://netflix.github.io/chaosmonkey/"
            rel="noreferrer" target="_blank" moz-do-not-send="true">https://netflix.github.io/chaosmonkey/</a><br>
          <br>
          No, chaos monkey is a purposeful thing to induce corner case
          errors so <br>
          they can be fixed. The earlier outage involved a config
          sanitizer that <br>
          screwed up and then pushed it out. I can't get my head around
          why <br>
          anybody thought that was a good idea vs rejecting it and
          making somebody <br>
          fix the config.<br>
          <br>
          Mike<br>
          <br>
          <br>
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                                style="line-height:1.71429;margin-top:0pt;margin-bottom:0pt"><span
style="color:rgb(51,51,51);font-family:helvetica;font-size:14px">Randy
                                  Monroe</span><br>
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                              <p
style="margin:0px;padding:0px;font-family:helvetica;font-size:14px;line-height:1.4;color:rgb(51,51,51)">Network
                                Engineering</p>
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                                  href="https://uber.com/"
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style="display:inline-block;max-width:none"><img alt="Uber"
src="https://s3.amazonaws.com/uber-static/emails/2018/global/logos/Uber_Logo_Black_RGB.png"
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