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Date: Sun, 07 Feb 2021 11:53:45 -0500
From: Stanley Lieber <sl@stanleylieber.com>
To: 9front@9front.org
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X-Bullshit: extended app persistence-based configuration reduce/map hosting 
Subject: Re: [9front] transient dns errors cause smtp failure
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On February 7, 2021 8:56:39 AM EST, kvik@a-b=2Exyz wrote:
>I think I found a reason for DNS failing on known good domains=2E
>
>/sys/src/cmd/ndb/dns=2Eh:156,157
>	/* tune; was 60*1000; keep it short */
>	Maxreqtm=3D	8*1000,	/* max=2E ms to process a request */
>
>So, 8 seconds is how much the resolver will bother with a request it
>has been handed, before dropping it on the floor with little
>explanation=2E
>
>It seems quite possible that this is too short a timeout on a machine
>during a spam queue run, which predictably stresses the compute and
>network resources=2E
>
>In turn, negative response caching might explain why a particular
>unlucky domain would basically stop receiveing any mail for a while=2E
>
>I'm dying to know if bumping this limit would clear up the queue of
>such DNS errors=2E
>
>

i cranked Maxreqtm to 30*1000 and it's already making a huge difference cl=
eaning out the queue=2E we'll see how it plays out=2E

thanks!

sl