[squid-dev] Valid document was not found in the cache and only-if-cached directive was specified. what does it mean?

[Eliezer Croitoru]

I am receiving this error page when a cache_peer is defined as a sibling on
each of the 2 proxies:
ERROR
The requested URL could not be retrieved
________________________________________
The following error was encountered while trying to retrieve the
URL: http://a7.org/Resize/pictures/187x113/757412.jpg
Valid document was not found in the cache and only-if-cached directive was
specified.
You have issued a request with a only-if-cached cache control directive. The
document was not found in the cache, or it required revalidation prohibited
by the only-if-cached directive.
Your cache administrator
is mailto:webmaster?subject=CacheErrorInfo%20-%20ERR_ONLY_IF_CACHED_MISS&bod
y=CacheHost%3A%20filter%0D%0AErrPage%3A%20ERR_ONLY_IF_CACHED_MISS%0D%0AErr%3
A%20%5Bnone%5D%0D%0ATimeStamp%3A%20Wed,%2001%20Mar%202017%2000%3A57%3A25%20G
MT%0D%0A%0D%0AClientIP%3A%2010.0.0.28%0D%0A%0D%0AHTTP%20Request%3A%0D%0AGET%
20%2FResize%2Fpictures%2F187x113%2F757412.jpg%20HTTP%2F1.1%0AUpgrade-Insecur
e-Requests%3A%201%0D%0AUser-Agent%3A%20Mozilla%2F5.0%20(Windows%20NT%2010.0%
3B%20WOW64)%20AppleWebKit%2F537.36%20(KHTML,%20like%20Gecko)%20Chrome%2F55.0
.2883.95%20YaBrowser%2F17.1.1.1004%20Yowser%2F2.5%20Safari%2F537.36%0D%0AAcc
ept%3A%20text%2Fhtml,application%2Fxhtml+xml,application%2Fxml%3Bq%3D0.9,ima
ge%2Fwebp,*%2F*%3Bq%3D0.8%0D%0AAccept-Encoding%3A%20gzip,%20deflate,%20sdch%
0D%0AAccept-Language%3A%20en,he%3Bq%3D0.8%0D%0ACache-Control%3A%20max-age%3D
259200,%20only-if-cached%0D%0AConnection%3A%20keep-alive%0D%0AHost%3A%20a7.o
rg%0D%0A%0D%0A%0D%0A.

________________________________________
Generated Wed, 01 Mar 2017 00:57:25 GMT by filter (squid/3.5.24)
##END OF PAGE

When I am removing the cache_peer line the file is being fetched.
I am not sure what should have happen and what went wrong.
This is a part of a test I am running to vetify  how would a clustered set
of squid will work with a load balancer infront of them and also to verify
how would the proxies would communicate via ICP and HTCP.
The cache proxy are using a glusterfs nfs mount and rock cache_dir.
In theory and by glusterfs benchmarks(I ran) the proxy should be able to
read faster over the glusterfs and in speeds above 10Gbps.
There is a split of a second theoretical slow down but in practice I have
yet to feel it on small scale.

I need your help to understand if this is a bug and if so what should be
done with it.

Eliezer

----
Eliezer Croitoru
Linux System Administrator
Mobile: +972-5-28704261
Email: eliezer at ngtech.co.il