<div dir="ltr">Yes, you are right, but I have also found another explanation for it, the SMALLDNAME constant that is preventing larger names to be cached. I was able to compile a version with a bigger value for this constant and could see the eviction metric changing. <div><br></div><div>Thanks for the answers :) </div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, Apr 12, 2021 at 6:03 PM Simon Kelley <<a href="mailto:simon@thekelleys.org.uk">simon@thekelleys.org.uk</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">It's not absolute, since they may have been caught at the end of cache<br>
lifetime upstream, but the Time To Live values of one second and five<br>
seconds in those records suggests it's going to be pretty hard for them<br>
to hang around in the dnsmasq cache long enough to be evicted.<br>
<br>
<br>
Simon.<br>
<br>
<br>
On 12/04/2021 15:03, Leonardo da Mata wrote:<br>
> Hello, thanks for the answer.<br>
> <br>
> The queries I sent are for AWS rds resolution names, I repeated the<br>
> experiments with a sample of simple urls and cache size of 2 and could<br>
> see the eviction metric.<br>
> <br>
> I think there might be something on the AWS rds that might prevent it<br>
> from being cached (Some data is redacted)<br>
> <br>
> dig <a href="http://prod-authdb.cluster-ro-h2dic5akfled.us-west-2.rds.amazonaws.com" rel="noreferrer" target="_blank">prod-authdb.cluster-ro-h2dic5akfled.us-west-2.rds.amazonaws.com</a><br>
> <<a href="https://urldefense.com/v3/__http://prod-authdb.cluster-ro-h2dic5akfled.us-west-2.rds.amazonaws.com__;!!Nn3RWQ1l!fBXF8tRpYFkLuTtl4PrzPu-P9_zJwPTWfjzqm2nNlu71uPwfT7OoctFKbAlQT0DMnP8$" rel="noreferrer" target="_blank">https://urldefense.com/v3/__http://prod-authdb.cluster-ro-h2dic5akfled.us-west-2.rds.amazonaws.com__;!!Nn3RWQ1l!fBXF8tRpYFkLuTtl4PrzPu-P9_zJwPTWfjzqm2nNlu71uPwfT7OoctFKbAlQT0DMnP8$</a> ><br>
> @<a href="http://172.0.0.1" rel="noreferrer" target="_blank">172.0.0.1</a> <<a href="https://urldefense.com/v3/__http://172.0.0.1__;!!Nn3RWQ1l!fBXF8tRpYFkLuTtl4PrzPu-P9_zJwPTWfjzqm2nNlu71uPwfT7OoctFKbAlQbdcrODk$" rel="noreferrer" target="_blank">https://urldefense.com/v3/__http://172.0.0.1__;!!Nn3RWQ1l!fBXF8tRpYFkLuTtl4PrzPu-P9_zJwPTWfjzqm2nNlu71uPwfT7OoctFKbAlQbdcrODk$</a> ><br>
> <br>
> ; <<>> DiG 9.11.4-P2-RedHat-9.11.4-26.P2.amzn2.4 <<>><br>
> <a href="http://prod-authdb.cluster-ro-h2dic5akfled.us-west-2.rds.amazonaws.com" rel="noreferrer" target="_blank">prod-authdb.cluster-ro-h2dic5akfled.us-west-2.rds.amazonaws.com</a><br>
> <<a href="https://urldefense.com/v3/__http://prod-authdb.cluster-ro-h2dic5akfled.us-west-2.rds.amazonaws.com__;!!Nn3RWQ1l!fBXF8tRpYFkLuTtl4PrzPu-P9_zJwPTWfjzqm2nNlu71uPwfT7OoctFKbAlQT0DMnP8$" rel="noreferrer" target="_blank">https://urldefense.com/v3/__http://prod-authdb.cluster-ro-h2dic5akfled.us-west-2.rds.amazonaws.com__;!!Nn3RWQ1l!fBXF8tRpYFkLuTtl4PrzPu-P9_zJwPTWfjzqm2nNlu71uPwfT7OoctFKbAlQT0DMnP8$</a> ><br>
> @<a href="http://172.0.0.1" rel="noreferrer" target="_blank">172.0.0.1</a> <<a href="https://urldefense.com/v3/__http://172.0.0.1__;!!Nn3RWQ1l!fBXF8tRpYFkLuTtl4PrzPu-P9_zJwPTWfjzqm2nNlu71uPwfT7OoctFKbAlQbdcrODk$" rel="noreferrer" target="_blank">https://urldefense.com/v3/__http://172.0.0.1__;!!Nn3RWQ1l!fBXF8tRpYFkLuTtl4PrzPu-P9_zJwPTWfjzqm2nNlu71uPwfT7OoctFKbAlQbdcrODk$</a> ><br>
> ;; global options: +cmd<br>
> ;; Got answer:<br>
> ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 60600<br>
> ;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 1<br>
> <br>
> ;; OPT PSEUDOSECTION:<br>
> ; EDNS: version: 0, flags:; udp: 4096<br>
> ;; QUESTION SECTION:<br>
> ;<a href="http://prod-authdb.cluster-ro-h2dic5akfled.us-west-2.rds.amazonaws.com" rel="noreferrer" target="_blank">prod-authdb.cluster-ro-h2dic5akfled.us-west-2.rds.amazonaws.com</a><br>
> <<a href="https://urldefense.com/v3/__http://prod-authdb.cluster-ro-h2dic5akfled.us-west-2.rds.amazonaws.com__;!!Nn3RWQ1l!fBXF8tRpYFkLuTtl4PrzPu-P9_zJwPTWfjzqm2nNlu71uPwfT7OoctFKbAlQT0DMnP8$" rel="noreferrer" target="_blank">https://urldefense.com/v3/__http://prod-authdb.cluster-ro-h2dic5akfled.us-west-2.rds.amazonaws.com__;!!Nn3RWQ1l!fBXF8tRpYFkLuTtl4PrzPu-P9_zJwPTWfjzqm2nNlu71uPwfT7OoctFKbAlQT0DMnP8$</a> >. IN<br>
> A<br>
> <br>
> ;; ANSWER SECTION:<br>
> <a href="http://prod-authdb.cluster-ro-h2dic5akfled.us-west-2.rds.amazonaws.com" rel="noreferrer" target="_blank">prod-authdb.cluster-ro-h2dic5akfled.us-west-2.rds.amazonaws.com</a><br>
> <<a href="https://urldefense.com/v3/__http://prod-authdb.cluster-ro-h2dic5akfled.us-west-2.rds.amazonaws.com__;!!Nn3RWQ1l!fBXF8tRpYFkLuTtl4PrzPu-P9_zJwPTWfjzqm2nNlu71uPwfT7OoctFKbAlQT0DMnP8$" rel="noreferrer" target="_blank">https://urldefense.com/v3/__http://prod-authdb.cluster-ro-h2dic5akfled.us-west-2.rds.amazonaws.com__;!!Nn3RWQ1l!fBXF8tRpYFkLuTtl4PrzPu-P9_zJwPTWfjzqm2nNlu71uPwfT7OoctFKbAlQT0DMnP8$</a> >. 1<br>
> IN CNAME <a href="http://prod-authdb-1.h2dic5akfled.us-west-2.rds.amazonaws.com" rel="noreferrer" target="_blank">prod-authdb-1.h2dic5akfled.us-west-2.rds.amazonaws.com</a><br>
> <<a href="https://urldefense.com/v3/__http://prod-authdb-1.h2dic5akfled.us-west-2.rds.amazonaws.com__;!!Nn3RWQ1l!fBXF8tRpYFkLuTtl4PrzPu-P9_zJwPTWfjzqm2nNlu71uPwfT7OoctFKbAlQrgNuWU8$" rel="noreferrer" target="_blank">https://urldefense.com/v3/__http://prod-authdb-1.h2dic5akfled.us-west-2.rds.amazonaws.com__;!!Nn3RWQ1l!fBXF8tRpYFkLuTtl4PrzPu-P9_zJwPTWfjzqm2nNlu71uPwfT7OoctFKbAlQrgNuWU8$</a> >.<br>
> <a href="http://prod-authdb-1.h2dic5akfled.us-west-2.rds.amazonaws.com" rel="noreferrer" target="_blank">prod-authdb-1.h2dic5akfled.us-west-2.rds.amazonaws.com</a><br>
> <<a href="https://urldefense.com/v3/__http://prod-authdb-1.h2dic5akfled.us-west-2.rds.amazonaws.com__;!!Nn3RWQ1l!fBXF8tRpYFkLuTtl4PrzPu-P9_zJwPTWfjzqm2nNlu71uPwfT7OoctFKbAlQrgNuWU8$" rel="noreferrer" target="_blank">https://urldefense.com/v3/__http://prod-authdb-1.h2dic5akfled.us-west-2.rds.amazonaws.com__;!!Nn3RWQ1l!fBXF8tRpYFkLuTtl4PrzPu-P9_zJwPTWfjzqm2nNlu71uPwfT7OoctFKbAlQrgNuWU8$</a> >. 5 IN A<br>
> 10.0.4.23<br>
> <br>
> ;; Query time: 49 msec<br>
> ;; SERVER: 172.0.0.1#53(172.0.0.1)<br>
> ;; WHEN: Mon Apr 12 12:55:08 UTC 2021<br>
> ;; MSG SIZE rcvd: 157<br>
> <br>
> <br>
> Is CNAME not cached? <br>
> <br>
> On Fri, Apr 9, 2021 at 10:46 PM Geert Stappers <<a href="mailto:stappers@stappers.nl" target="_blank">stappers@stappers.nl</a><br>
> <mailto:<a href="mailto:stappers@stappers.nl" target="_blank">stappers@stappers.nl</a>>> wrote:<br>
> <br>
> On Fri, Apr 09, 2021 at 10:39:41AM +0100, Leonardo da Mata wrote:<br>
> > On Thu, Apr 8, 2021 at 10:50 PM Simon Kelley wrote:<br>
> > > On 08/04/2021 10:37, Leonardo da Mata wrote:<br>
> > > > Hello, recently I've done some experiments with dnsmasq<br>
> reaching 4k qps<br>
> > > > and, even with a very small cache size of 100 entries, I can't<br>
> see the<br>
> > > > evictions stats to increase. It always stays at zero.<br>
> > > ><br>
> > > > I'm wondering if anyone can see this data on their side and if<br>
> there<br>
> > > > might be any problem with the statistics count or something<br>
> that might<br>
> > > > interfere with this data.<br>
> > > ><br>
> > ><br>
> > > Thu Apr 8 21:33:08 2021 <a href="http://daemon.info" rel="noreferrer" target="_blank">daemon.info</a> <<a href="https://urldefense.com/v3/__http://daemon.info__;!!Nn3RWQ1l!fBXF8tRpYFkLuTtl4PrzPu-P9_zJwPTWfjzqm2nNlu71uPwfT7OoctFKbAlQOMriH8A$" rel="noreferrer" target="_blank">https://urldefense.com/v3/__http://daemon.info__;!!Nn3RWQ1l!fBXF8tRpYFkLuTtl4PrzPu-P9_zJwPTWfjzqm2nNlu71uPwfT7OoctFKbAlQOMriH8A$</a> ><br>
> dnsmasq[23124]: cache size 600,<br>
> > > 58/15779 cache insertions re-used unexpired cache entries.<br>
> > ><br>
> > ><br>
> > > What are you using as your test query set?<br>
> > ><br>
> > ><br>
> ><br>
> > I'm using a sample of queries from my services, but I'm introducing an<br>
> > artificial qps with flame using this sample.<br>
> ><br>
> <br>
> FWIW "this sample" did not reach my end of the Internet.<br>
> <br>
> <br>
> Please recieve<br>
> > > What are you using as your test query set?<br>
> as<br>
> } } Send your test query set, so we can reproduce the observation.<br>
> <br>
> <br>
> <br>
> Groeten<br>
> Geert Stappers<br>
> -- <br>
> Silence is hard to parse<br>
> <br>
> <br>
> <br>
> -- <br>
> Leonardo da Mata<br>
> <<a href="https://urldefense.com/v3/__http://goog_881972804/__;!!Nn3RWQ1l!fBXF8tRpYFkLuTtl4PrzPu-P9_zJwPTWfjzqm2nNlu71uPwfT7OoctFKbAlQwhtzT8k$" rel="noreferrer" target="_blank">https://urldefense.com/v3/__http://goog_881972804/__;!!Nn3RWQ1l!fBXF8tRpYFkLuTtl4PrzPu-P9_zJwPTWfjzqm2nNlu71uPwfT7OoctFKbAlQwhtzT8k$</a> ><br>
> <a href="mailto:leonardo.mata@samsara.com" target="_blank">leonardo.mata@samsara.com</a> <mailto:<a href="mailto:leonardo.mata@samsara.com" target="_blank">leonardo.mata@samsara.com</a>><br>
> <br>
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</blockquote></div><br clear="all"><div><br></div>-- <br><div dir="ltr" class="gmail_signature"><div dir="ltr"><div>Leonardo da Mata<a href="http://goog_881972804/" target="_blank"><br></a></div><div><a href="mailto:leonardo.mata@samsara.com" target="_blank">leonardo.mata@samsara.com</a></div></div></div>