varnish suddenly restarting / flushing itself after several hours?

[Frank van Lingen]

Hello,

After setting up varnish and starting it I looked at the statistics
using varnsihstat. The timer in the left uppper corner seems to be the
uptime since it last started or was flushed. When I loaded some pages,
I can see the cache is working

But I notice that once every so often the cache seems to either flush
itself or restart. During this 2-3 seconds that this happens I can not
load any pages.

Is there a default 'cash flush' value that makes this (for me
undesirable) behavior happen?

I added the example described in
http://varnish.projects.linpro.no/wiki/VCLExampleLongerCaching to my
vcl file, but if the cash flushes itself a couple of times per day
then it defeats the purpose.

I am using varnish-2.0.5-1.el5 on centos5 and use the default.vcl file
with the above longer caching example added to it and ignore swf and
pdf files. I start varnish with 40 MB of cache and test this with a
few html pages and jpgs (less then 15 MB in size). During tests
normally not more than 50% of the cache is used.

Besides this issue varnish seems to work almost right out of the box.

Frank.