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From Pedro David Marco <pedrod_ma...@yahoo.com>
Subject Re: Random results with AskDns
Date Tue, 02 Mar 2021 15:26:42 GMT
 SOLVED!
Just in case someone has this issue...  
Short version:
In heavy load environments, SA produces more UDP traffic (specially if answers are big, typically
happens with TXT queries) than Linux kernel can handlewith default buffers (tested in Debian
Buster), so many SA queries never get an answer and die on timeout.This not only affects final
SA result, but performance.
Correct Kernel UD tunning solves the problem!
-----------Pedreter.

   On Monday, March 1, 2021, 06:06:24 PM GMT+1, Pedro David Marco <pedrod_marco@yahoo.com>
wrote:  
 >Hi all,>When there are several hundreds of lookups, Askdns / Async abort many of them
randomly even when 100% of queries got an answer.
>I use local dns cache but every run of SA produces different number of aborted remaining
lookups. >if you dig manually from command line any aborted query, answer is immediate.
>I have not found any related bug in SA Bugzilla.. (pretty similar to this one  7875
– AskDNS plugin does not correctly handle CNAMEs leading to TXTs  ) 
>After some debug, it seems that answers are not harvested properly... and around 30% of
them are lost in every run.
>It is not a timeout problem: both tcpdump and dns-cache log  show immediate answers to
100% of queries in less than 1 second.
>May this be solved in the new AskDns John Hardin mentioned some days ago?

  
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