[squid-users] Some requests not being passed/processed by squid

[Ralf Hildebrandt]

We're running a cluster of 4 identical Squid proxies.

In order to check the functionality of each cluster node, were using
ldirectord which is querying each realserver like this:

GET http://127.0.0.1/proxytest.cgi 

Now we were seen some odd warning in our graphs, clusternodes being
removed and added back to the cluster only a few seconds later.

I found that these requests for http://127.0.0.1/proxytest.cgi were
sometimes (seldom -- maybe once/twice per day) failing.

In the squid access.log I'm seeing this as:
===========================================

Thu Aug 10 10:32:54 2023    115 141.42.5.218 TCP_REFRESH_ABORTED/200 0 141 GET http://127.0.0.1/proxytest.cgi - HIER_DIRECT/127.0.0.1 text/plain accessRule=- 56680
Thu Aug 10 10:33:02 2023      0 141.42.5.218 NONE_NONE_ABORTED/000 0 141 GET http://127.0.0.1/proxytest.cgi - HIER_NONE/- - accessRule=- -
Thu Aug 10 10:33:07 2023      0 141.42.5.218 NONE_NONE_ABORTED/000 0 141 GET http://127.0.0.1/proxytest.cgi - HIER_NONE/- - accessRule=- -

as opposed to the normal:
=========================

Thu Aug 10 11:02:45 2023      5 141.42.5.218 TCP_REFRESH_MODIFIED/200 314 141 GET http://127.0.0.1/proxytest.cgi - HIER_DIRECT/127.0.0.1 text/plain accessRule=- 51940

My Logformat:
=============

logformat squid-sourceport  %ts.%03tu %6tr %>a %Ss/%03>Hs %<st %>st %rm %ru %[un %Sh/%<a %mt accessRule=%{accessRule}note %<lp

* I replaced the the secondssince1970 timestamp with a human readable timeformat
* Last colument in the log is the sourceport used by squid 

I checked nginx logs on that machine and found that the requests for
http://127.0.0.1/proxytest.cgi never reached nginx (for the three
incidents marked above)

So my questions:
================

What are TCP_REFRESH_ABORTED/200 and (which looks more dire) NONE_NONE_ABORTED/000?

-- 
Ralf Hildebrandt
Charité - Universitätsmedizin Berlin
Geschäftsbereich IT | Abteilung Netzwerk

Campus Benjamin Franklin (CBF)
Haus I | 1. OG | Raum 105
Hindenburgdamm 30 | D-12203 Berlin

Tel. +49 30 450 570 155
ralf.hildebrandt at charite.de
https://www.charite.de