[squid-users] TCP_MISS in images

[Yuri Voinov]

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23.07.15 23:57, Amos Jeffries пишет:
> On 24/07/2015 4:02 a.m., Ulises Nicolini wrote:
>> Hello,
>>
>> I have a basic squid 3.5 configuration with
>>
>> maximum_object_size_in_memory 64 KB
>> maximum_object_size 100000 KB
>> minimum_object_size 512 bytes
>>
>> refresh_pattern -i \.(gif|png|jpg|jpeg|ico)$ 1440 90% 10080
>> override-expire ignore-no-cache ignore-private
>> refresh_pattern -i (/cgi-bin/)                  0       0%      0
>> refresh_pattern .                                       0 20%     4320
>>
>
> ignore-no-cache has no meaning for Squid-3.5.
>
> ignore-private does nothing on your images. It makes current Squid act
> like must-revalidate was set on the response instead of "private".
>
> override-expire also does nothing on your images. As used above it makes
> Squid act like "s-maxage=604800" was given instead of any Expires:
> header or max-age=N / s-maxage=N Cache-Control values.
>
>
>>
>> cache_dir rock  /cache1/rock1 256  min-size=500 max-size=32767
>> max-swap-rate=250 swap-timeout=350
>> cache_dir diskd /cache2/diskd1 1000 16 256 min-size=32768
max-size=1048576
>> cache_dir diskd /cache2/diskd2 100000 16 256 min-size=1048576
>>
>>
>> But when I test it against my webserver, using only one client PC, the
>> only thing I get are TCP_MISSes of my images.
>>
>> 1437664284.339     11 192.168.2.103 TCP_MISS/200 132417 GET
>> http://test-server.com/images/imagen3.jpg - HIER_DIRECT/192.168.2.10
>> image/jpeg
>> 1437664549.753      5 192.168.2.103 TCP_MISS/200 53933 GET
>> http://test-server.com/images/imagen1.gif - HIER_DIRECT/192.168.2.10
>> image/gif
>> 1437665917.469     18 192.168.2.103 TCP_MISS/200 8319 GET
>> http://test-server.com/images/icono.png - HIER_DIRECT/192.168.2.10
>> image/png
>>
>> The response headers don't have Vary tags or any other that may impede
>> caching
>>
>> Accept-Ranges    bytes
>> Connection    close
>> Content-Length    53644
>> Content-Type    image/gif
>> Date    Thu, 23 Jul 2015 15:56:07 GMT
>> Etag    "e548d4-d18c-51b504b95dec0"
>> Last-Modified    Mon, 20 Jul 2015 15:36:03 GMT
>> Server    Apache/2.2.22 (EL)
>>
>
> Your refresh pattern says to only cache these objects for +90% of their
> current age, so long as that period is longer than 1 day (1440 mins) and
> no more that 7 days (10080 mins).
>
> Which means;
>  they are 3 days 20 mins 4 secs old right now (260404 secs).
>  90% of that is 2 days 17 hrs 6 mins 3 secs (234363 secs).
>
> So the object "e548d4-d18c-51b504b95dec0" will stay in cache for the
> next 2 days 17hrs etc.
>
> I notice though that the Content-Length size does not match any of the
> logged transfer sizes. Which makes me wonder if the object is actually
> varying despite the lack of Vary headers.
>
>
>>
>> Is it necessary a certain amount of requests of a single object to be
>> cached (mem o disk) or am I facing some other problem here?
>
> Yes. Two requests. The first (a MISS) will add it to cache the second
> and later should be HITs on the now cached object.
>
> BUT, only if you are not force-reloading the browser for your tests.
> Force-reload instructs Squid it ignore its cached content and replace it
> with another MISS.
Amos, this behaviour depends from refresh_pattern and often can be
ignore (with reload-into-ims, for example).
>
>
>
> Amos
> _______________________________________________
> squid-users mailing list
> squid-users at lists.squid-cache.org
> http://lists.squid-cache.org/listinfo/squid-users

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