[squid-users] How long this object should be left in the cache?

[Eliezer Croitoru]

I had to tune up couple things and I have a question about a HEAD request I
have seen since something doesn't make sense in them.
I have the following line in the access log:
1499068883.928    163 192.168.168.102 TCP_MISS/200 522 HEAD
http://download.windowsupdate.com/d/msdownload/update/software/updt/2016/03/
windows6.1-kb3147071-x64_18992bd5fa0424684c4872e1c10f5663b6d3aa52.psf -
HIER_DIRECT/8.253.70.46 application/octet-stream Q-CC: "-" "-" Q-P: "-" "-"
REP-CC: "public,max-age=172800" REP-EXP: "Sat, 05 Nov 2016 03:50:11 GMT"
VARY: "-" 52:54:00:bc:e3:78 CacheHeader: "MISS from localhost.localdomain"

And I am using this logformat to get it:
logformat cache_headers %ts.%03tu %6tr %>a %Ss/%03>Hs %<st %rm %ru %[un
%Sh/%<a %mt Q-CC: "%{Cache-Control}>h" "%{Cache-Control}>ha" Q-P:
"%{Pragma}>h" "%{Pragma}>ha" REP-CC: "%{Cache-Control}<h" REP-EXP:
"%{Expires}<h" VARY: "%{Vary}<h" %>eui CacheHeader: "%{X-Cache}<h"
access_log daemon:/var/log/squid/access.log cache_headers

I am not sure if I am seeing right or wrong and if these are real, what is
expected or how it should be treated since:
- the expires header is I the past.... 
- and against to this it's a public object with a very long maximum age.

How should squid handle this request what is expected from squid in this
confusing situation?

Thanks,
Eliezer

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