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The answer is simple.<br>
<br>
Look ath this row from 3.5.10 access.log:<br>
<br>
1445879345.827 48 127.0.0.1 TCP_MEM_HIT/200 24425 GET
<a class="moz-txt-link-freetext" href="https://upload.wikimedia.org/wikipedia/commons/thumb/8/8c/Teller-Ulam_device.png/200px-Teller-Ulam_device.png">https://upload.wikimedia.org/wikipedia/commons/thumb/8/8c/Teller-Ulam_device.png/200px-Teller-Ulam_device.png</a>
- HIER_NONE/- image/png<br>
<br>
We can see a big enoug image from Wiki. Mem hit, yea?<br>
<br>
With next request we got TCP_HIT, when image comes from disk cache
after swap out.<br>
<br>
Refresh pattern from 3.5.10 related to this URL:<br>
<br>
# Other long-lived items<br>
refresh_pattern -i
\.(jp(e?g|e|2)|gif|png|tiff?|bmp|ico|svg|webp|flv|f4f|mp4|ttf|eot|woff2?)(\?.*)?$
14400 99% 518400 override-expire override-lastmod
reload-into-ims ignore-private ignore-no-store<br>
<br>
Then we look in 4.0.1 access.log with the same image:<br>
<br>
14458854979.432 48 127.0.0.1 TCP_MISS/200 24425 GET
<a class="moz-txt-link-freetext" href="https://upload.wikimedia.org/wikipedia/commons/thumb/8/8c/Teller-Ulam_device.png/200px-Teller-Ulam_device.png">https://upload.wikimedia.org/wikipedia/commons/thumb/8/8c/Teller-Ulam_device.png/200px-Teller-Ulam_device.png</a>
- HIER_NONE/- image/png<br>
<br>
# Other long-lived items<br>
refresh_pattern -i
\.(jp(e?g|e|2)|gif|png|bmp|ico|svg|web(p|m)|flv|f4f|mp(3|4)|ttf|eot|woff2?))(\?.*)?$
14400 100% 518400 override-expire override-lastmod
reload-into-ims ignore-private ignore-no-store<br>
<br>
Did you see principal difference? Ah, yes. 4.0.1 has more than 4
times bigger mem_cache, 1 Gb. 1st example 3.5.10 has only 256
Mbytes. This is the reason of miss??????<br>
<br>
Both servers has the similar squid.conf. Both images are static.<br>
<br>
Well, now we goes to redbot.org and check this URL:<br>
<br>
<a class="moz-txt-link-freetext" href="http://i.imgur.com/KiydfT0.png">http://i.imgur.com/KiydfT0.png</a><br>
<br>
What we seen?<br>
<br>
<br>
Caching<br>
<br>
* This response allows all caches to store it.<br>
* This response cannot be served from cache without validation.<br>
<br>
So, what's wrong with Squid NOW?<br>
<br>
Interesting, isn't it?<br>
<br>
26.10.15 23:01, Alex Rousskov пишет:<br>
<span style="white-space: pre;">> On 10/26/2015 04:41 AM, Yuri
Voinov wrote:<br>
><br>
>> what has changed so much that the same<br>
>> configuration I get 10 times smaller cache hit.<br>
><br>
> You are asking a good question. I do not think anybody knows
the exact<br>
> answer -- too many things have changed in general to either
identify the<br>
> changes that have affected your [complicated] setup or to
exclude all of<br>
> the changes and blame some yet-unknown v4 bug.<br>
><br>
><br>
> However, the following procedure is almost guaranteed to lead
you to the<br>
> answer:<br>
><br>
> 1. Find a URL/resource that was served from the cache in v3
but became a<br>
> miss in v4. You probably have access.logs that can be used
for that. If<br>
> not, enable them and run more experiments. Since your drop in
hit ratio<br>
> is so drastic, it should not take long to find a URL that was
usually a<br>
> hit before and is usually a miss now (or that becomes a
hit/miss as soon<br>
> as you switch to v3/4).<br>
><br>
> 2. Reproduce the v4 miss with an ALL,9 cache.log and share
that log. Do<br>
> this using single-transaction command-line tools, with no
other traffic<br>
> going through Squid. Others on this list can guide you as to
what<br>
> logging options to use if you do not want to run with ALL,9.<br>
><br>
> The above requires some work on your part. It is a good idea
to run<br>
> these tests in a non-production environment (which may
require even more<br>
> work from you). Needless to say, you are not required to do
that extra<br>
> work. However, some extra work is most likely required if you
want to<br>
> get the answer to your question because there is currently
not enough<br>
> information to answer it.<br>
><br>
><br>
> HTH,<br>
><br>
> Alex.<br>
></span><br>
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