Re: No ICP Replies

Rainer Klier wrote:

> Hi there,
>
> we are working with squid 1.1.16 and the only parentproxy we can contact
> is a netscape 2.53 proxy. Our squid.conf says:
>
> cache_host proxy1.fth.sbs.de parent 81 7 weight=10 no-query default
>
> As far as I know, no ICP replies should be sent to this proxy. But
> often we get: No ICP replies an the host is beyond the firewall.
> The logfile says something like:
> 881217134.637 45 145.121.100.6 ERR_CANNOT_FETCH/400 966 GET http://www.owo.com/main.html - NO_DIRECT_FAIL/www.owo.com -
>
> Are there any ICP requests sent to this parentproxy ? In case yes: what
> do I have to do, to avoid this problem ? In fact the parentproxy is

In theory no. If you have single_parent_bypass on then _absolutely_ not.

> never down in this time we do get those messages (a telnet proxy1.fth.sbs.de 81
> works without probs). Another proxyadmin said, that an upgrade to 1.1.18
> wouldn't help.
>

Look in your cache_log for an entry like 'TCP connection failed to proxy1.fth.sbs.de:81'

That'll be your culprit. A connection is not getting opened properly, and Squid is marking the host as unreachable for several
minutes (during which it spits that particular error message). After a few minutes it tries to reestablish contact and
succeeds, and all goes back to normal. It's demoralising for the users.

I have a 1-byte patch to one source file that makes this go away, by ignoring the negative caching in this circumstance. It can
be cleaner. It _should_ be. I should have patched it so that it would only cheat if there was a single parent only.

Nevertheless:

In squid 1.1.17

neighbors.c, line 1148 it says: p->tcp_up=0;

Change it to: p->tcp_up=1;

And your problem will largely go away. The odd connection will fail, but they will never mark the host as unreachable.
You could _try_ recompiling with -DRETRY_CONNECT=1 but I suspect that that code is largely untried, and probably unsafe for a
production system. Duane? You'd know.

Good luck.

D

> Thanx in advance,
>
> Rainer
>
> --
> ______
> /| | Rainer Klier | Wahr sind auch die Erinnerungen, die wir mit
> / |__ | Thomas-Mann-Str. 6| uns tragen, die Traeume, die wir spinnen,
> | /__/| | 90763 Fuerth | und die Sehnsuechte, die uns treiben. Damit
> | | ||__| Germany | wollen wir uns bescheiden.
> | |__|/ / email : klier@kwu.siemens.de H.Spoerl
> |/______/ rrklier@tychen.franken.de
> URL : http://www.franken.de/users/tychen/rrklier/

--
Note to evil sorcerers and mad scientists: don't ever, ever summon powerful
demons or rip holes in the fabric of space and time. It's never a good idea.
ICQ UIN: 3225440