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Le 16/09/2011 08:55, Jorge Nerín a écrit :
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cite="mid:CAF-dNMaKvvxnHCiTR2-jVQyRC9s7Bi4J81hUTh7x1RW9-___Jw@mail.gmail.com"
type="cite"><br>
<div class="gmail_quote">On Thu, Sep 15, 2011 at 11:29, Aurélien
Lemaire <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:aurelien.lemaire@smile.fr">aurelien.lemaire@smile.fr</a>></span>
wrote:<br>
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<div bgcolor="#ffffff" text="#000000"> Good day folks,<br>
<br>
First of all, varnish is an outstanding piece of software
that my company and i are addicted to. So thanks to all the
coders.<br>
<br>
Here is my problem :<br>
I allocated varnish 1G of RAM on a website that can have
more than 2 Go of possible cacheable objects . Not to worry
though as any proxy-cache system should smartly nuke old
objects to make place to new one to live peacefully within
its allocated RAM. And that's where Varnish behave
unexpectedly : each time it need to nuke SOME objects : it
nukes ALMOST ALL of them (often ~80% of my 35k objects)
which is quite aggressive ; thus i lost almost all my
cache....IRK !<br>
<br>
3 Munin graphs attached to see the problem clearly : big
drop each time a nuking happens.<br>
<br>
To make sure my pbr is about varnish nuking system : i
increased from 1G to 3G(more than the max possible 2G
cacheable objects) on another varnish of this platefom (this
website is delivered by multiple front/varnish server all
stricly similar and independant) and this issue disappeared
(no more nuking : no lost of ~80%of my objects)<br>
<br>
Here is my env : <br>
Debian 5.0.8 64 bits on 2.6.32-5-openvz-amd64 kernel<br>
Varnish 2.1.3 SVN 5049:5055(debian package 2.1.3-8) <br>
200 varnish 's worker threads running constantly (no issue
on workers)<br>
30req/s average with 60/s in peak<br>
<br>
Daemon run as such :<br>
/usr/sbin/varnishd -P /var/run/varnishd.pid -a :80 -T
localhost:6082 -S /etc/varnish/secret -f
/etc/varnish/serverx.vcl -w 100,1024 -s
file,/var/lib/varnish/serverx/varnish_storage.bin,3G<br>
<br>
Here a quick varnishstat -1 :<br>
<br>
Is it normal varnish behaviour ? sounds like a bug to me.<br>
Am i missing some tuning (lru_interval) to soften the
nuking algo ?<br>
Do you need more info ?<br>
helps appreciated here ;-)<br>
<br>
Regards, Aurelien Lemaire<br>
</div>
<br>
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</div>
<br>
It could be someone downloading a large file (like a ~700Mb iso
file) and varnish nuking objects to make room for this file (even
if its configured to not cache it).<br>
<br>
Try to get a varnishlog trace of the moment the nuking begins.<br
clear="all">
<br>
-- <br>
Jorge Nerín<br>
<<a moz-do-not-send="true" href="mailto:jnerin@gmail.com">jnerin@gmail.com</a>><br>
</blockquote>
This website does not content any files bigger than a couple of Mb.
<br>
<br>
Will see what i can do to get the varnishlog during the nuking.<br>
<br>
--<br>
aurelien lemaire<br>
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