<div dir="ltr">Varnish may be marking your backend as "unhealthy" because you're failing too many health probes during this phase. When Varnish does backend health polling, it opens a <i>new</i> tcp connection to the backend with a preconfigured request.<div>
<div><br></div><div style>I would increase the timeout, window, and/or threshold to see if you can rule this out. You can read more about backend polling <a href="https://www.varnish-cache.org/trac/wiki/BackendPolling">here</a>.</div>
</div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Sun, Feb 10, 2013 at 6:35 AM, Tristan CHARBONNIER @ Crealya <span dir="ltr"><<a href="mailto:charbonnier@crealya.com" target="_blank">charbonnier@crealya.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div lang="EN-US" link="#0563C1" vlink="#954F72"><div><p class="MsoNormal">Hello,<u></u><u></u></p><p class="MsoNormal">
<u></u> <u></u></p><p class="MsoNormal">First, I want to thanks everyone who is contributing to this great piece of software! Indeed, it’s working very well and it’s very efficient.<u></u><u></u></p><p class="MsoNormal">
<u></u> <u></u></p>
<p class="MsoNormal">I just encounter a small problem : I use varnish/squeeze v2.1.3-8 on a Debian Linux 6.0 web server with the kernel v2.6.32-5-amd64.<u></u><u></u></p><p class="MsoNormal">I use Virtualmin to manage this webserver and I set up Varnish on top of apache2/squeeze v2.2.16-6+squeeze10.<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p><p class="MsoNormal">During the logrotate process, Varnish gives 503 errors. I traced the problem to the multiple apache2 graceful restart that are done during this process.<u></u><u></u></p>
<p class="MsoNormal">Indeed, I host plenty of websites (more than 100) on my web server and, for each one, I have a block like this in my ‘/etc/logrotate.conf’ file:<u></u><u></u></p><p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">/var/log/virtualmin/mywebsite.fr_access_log /var/log/virtualmin/mywebsite.fr_error_log {<u></u><u></u></p><p class="MsoNormal"> rotate 5<u></u><u></u></p><p class="MsoNormal"> weekly<u></u><u></u></p>
<p class="MsoNormal"> compress<u></u><u></u></p><p class="MsoNormal"> postrotate<u></u><u></u></p><p class="MsoNormal"> /usr/sbin/apache2ctl graceful ; sleep 5<u></u><u></u></p><p class="MsoNormal"> endscript<u></u><u></u></p>
<p class="MsoNormal">}<u></u><u></u></p><p class="MsoNormal"><u></u> <u></u></p><p class="MsoNormal">So, during the logrotate process (which lasts for 20 minutes), there is 100+ graceful restart of apache. ‘graceful restart’ are not supposed to terminate existing connections so I don’t understand why Varnish fails to work: probably a mistake on my side!<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p><p class="MsoNormal">In my VCL file, I just have “backend apache { .host = "88.190.19.00"; .port = "8080"; }” block along with the usual ones (acl purge, vcl_fetch, …). I use the default Varnish configuration file, except that I raised the memory to 4G and use ram to store the cache.<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p><p class="MsoNormal">Any clue on how I can solve this small problem?<u></u><u></u></p><p class="MsoNormal"><u></u> <u></u></p><p class="MsoNormal">Thanks in advance,<span class="HOEnZb"><font color="#888888"><u></u><u></u></font></span></p>
<span class="HOEnZb"><font color="#888888"><p class="MsoNormal"><u></u> <u></u></p><p class="MsoNormal">Tristan CHARBONNIER<u></u><u></u></p><p class="MsoNormal"><u></u> <u></u></p><p class="MsoNormal"><u></u> <u></u></p>
</font></span></div></div><br>_______________________________________________<br>
varnish-misc mailing list<br>
<a href="mailto:varnish-misc@varnish-cache.org">varnish-misc@varnish-cache.org</a><br>
<a href="https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc" target="_blank">https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc</a><br></blockquote></div><br></div>