[squid-users] IPv4 addresses go missing - markAsBad wrong?

Mon Feb 12 11:48:54 UTC 2024

What distro are you using?

בתאריך יום ב׳, 12 בפבר׳ 2024, 13:47, מאת Stephen Borrill ‏<
squid at borrill.org.uk>:

> On 16/01/2024 14:37, Alex Rousskov wrote:
> > On 2024-01-16 06:01, Stephen Borrill wrote:
> >> The problem is no different with 6.6. Is there any more debugging I
> >> can provide, Alex?
> >
> > Yes, but I need to give you a patch that adds that (temporary) debugging
> > first (assuming I fail to reproduce the problem in the lab). The ball is
> > on my side (unless somebody else steps in). Unfortunately, I do not have
> > any free time for any of that right now. If you do not hear from me
> > sooner, please ping me again on or after February 8, 2024.
>
> PING!
>
> I will get 6.7 compiled up so we can add debugging to it quickly. It
> would be good if we could get something in place this week as it is
> school holidays next week in the UK and so there will be little
> opportunity to test until afterwards.
>
> >> On 10/01/2024 12:40, Stephen Borrill wrote:
> >>> On 09/01/2024 15:42, Alex Rousskov wrote:
> >>>> On 2024-01-09 05:56, Stephen Borrill wrote:
> >>>>> On 09/01/2024 09:51, Stephen Borrill wrote:
> >>>>>> On 09/01/2024 03:41, Alex Rousskov wrote:
> >>>>>>> On 2024-01-08 08:31, Stephen Borrill wrote:
> >>>>>>>> I'm trying to determine why squid 6.x (seen with 6.5) connected
> >>>>>>>> via IPv4-only periodically fails to connect to the destination
> >>>>>>>> and then requires a restart to fix it (reload is not sufficient).
> >>>>>>>>
> >>>>>>>> The problem appears to be that a host that has one address each
> >>>>>>>> of IPv4 and IPv6 occasionally has its IPv4 address go missing as
> >>>>>>>> a destination. On closer inspection, this appears to happen when
> >>>>>>>> the IPv6 address (not the IPv4) address is marked as bad.
> >>>>
> >>>>> ipcache.cc(990) have: [2001:4860:4802:32::78]:443 at 0 in
> >>>>> 216.239.38.120 #1/2-0
> >>>>
> >>>>
> >>>> Thank you for sharing more debugging info!
> >>>
> >>> The following seemed odd to. It finds an IPv4 address (this host does
> >>> not have IPv6), puts it in the cache and then says "No DNS records":
> >>>
> >>> 2024/01/09 12:31:24.020 kid1| 14,4| ipcache.cc(617) nbgethostbyname:
> >>> schoolbase.online
> >>> 2024/01/09 12:31:24.020 kid1| 14,3| ipcache.cc(313) ipcacheRelease:
> >>> ipcacheRelease: Releasing entry for 'schoolbase.online'
> >>> 2024/01/09 12:31:24.020 kid1| 14,5| ipcache.cc(670)
> >>> ipcache_nbgethostbyname_: ipcache_nbgethostbyname: MISS for
> >>> 'schoolbase.online'
> >>> 2024/01/09 12:31:24.020 kid1| 14,3| ipcache.cc(480) ipcacheParse: 1
> >>> answers for schoolbase.online
> >>> 2024/01/09 12:31:24.020 kid1| 14,7| ipcache.cc(995) have:  no
> >>> 20.54.32.34 in [no cached IPs]
> >>> 2024/01/09 12:31:24.020 kid1| 14,7| ipcache.cc(995) have:  no
> >>> 20.54.32.34 in [no cached IPs]
> >>> 2024/01/09 12:31:24.020 kid1| 14,5| ipcache.cc(549) updateTtl: use
> >>> first 69 from RR TTL 69
> >>> 2024/01/09 12:31:24.020 kid1| 14,3| ipcache.cc(535) addGood:
> >>> schoolbase.online #1 20.54.32.34
> >>> 2024/01/09 12:31:24.020 kid1| 14,7| ipcache.cc(253) forwardIp:
> >>> 20.54.32.34
> >>> 2024/01/09 12:31:24.020 kid1| 44,2| peer_select.cc(1174) handlePath:
> >>> PeerSelector72389 found conn564274 local=0.0.0.0
> >>> remote=20.54.32.34:443 HIER_DIRECT flags=1, destination #1 for
> >>> schoolbase.online:443
> >>> 2024/01/09 12:31:24.020 kid1| 14,3| ipcache.cc(459) latestError:
> >>> ERROR: DNS failure while resolving schoolbase.online: No DNS records
> >>> 2024/01/09 12:31:24.020 kid1| 14,3| ipcache.cc(586)
> >>> ipcacheHandleReply: done with schoolbase.online: 20.54.32.34 #1/1-0
> >>> 2024/01/09 12:31:24.020 kid1| 14,7| ipcache.cc(236) finalCallback:
> >>> 0x1b7381f38  lookup_err=No DNS records
> >>>
> >>> It seemed to happen about the same time as the other failure, so
> >>> perhaps another symptom of the same.
> >>>
> >>>> The above log line is self-contradictory AFAICT: It says that the
> >>>> cache has both IPv6-looking and IPv4-looking address at the same
> >>>> cache position (0) and, judging by the corresponding code, those two
> >>>> IP addresses are equal. This is not possible (for those specific IP
> >>>> address values). The subsequent Squid behavior can be explained by
> >>>> this (unexplained) conflict.
> >>>>
> >>>> I assume you are running official Squid v6.5 code.
> >>>
> >>> Yes, compiled from source on NetBSD. I have the patch I refer to here
> >>> applied too:
> >>>
> https://lists.squid-cache.org/pipermail/squid-users/2023-November/026279.html
> >>>
> >>>> I can suggest the following two steps for going forward:
> >>>>
> >>>> 1. Upgrade to the latest Squid v6 in hope that the problem goes away.
> >>>
> >>> I have just upgraded to 6.6.
> >>>
> >>>> 2. If the problem is still there, patch the latest Squid v6 to add
> >>>> more debugging in hope to explain what is going on. This may take a
> >>>> few iterations, and it will take me some time to produce the
> >>>> necessary debugging patch.
> >>>
> >>> Unfortunately, I don't have a test case that will cause the problem
> >>> so I need to run this at a customer's production site that is
> >>> particularly affected by it. Luckily, the problem recurs pretty
> quickly.
> >>>
> >>> Here's a run with 6.6 where the number of destinations drops from 2
> >>> to 1 before reverting. Not seen this before - usually once it has
> >>> dropped to 1 (the IPv6 address), it stays there until a restart (and
> >>> this did happen about a minute after this log fragment). Happy to
> >>> test out any debugging patch.
> >>>
> >>> 2024/01/10 11:55:49.849 kid1| 14,4| ipcache.cc(617) nbgethostbyname:
> >>> forcesafesearch.google.com
> >>> 2024/01/10 11:55:49.849 kid1| 14,3| Address.cc(389) lookupHostIP:
> >>> Given Non-IP 'forcesafesearch.google.com': hostname or servname not
> >>> provided or not known
> >>> 2024/01/10 11:55:49.849 kid1| 14,4| ipcache.cc(657)
> >>> ipcache_nbgethostbyname_: ipcache_nbgethostbyname: HIT for
> >>> 'forcesafesearch.google.com'
> >>> 2024/01/10 11:55:49.849 kid1| 14,7| ipcache.cc(253) forwardIp:
> >>> [2001:4860:4802:32::78]
> >>> 2024/01/10 11:55:49.849 kid1| 44,2| peer_select.cc(1174) handlePath:
> >>> PeerSelector300176 found conn2388484 local=[::]
> >>> remote=[2001:4860:4802:32::78]:443 HIER_DIRECT flags=1, destination
> >>> #1 for forcesafesearch.google.com:443
> >>> 2024/01/10 11:55:49.849 kid1| 44,2| peer_select.cc(1180) handlePath:
> >>> always_direct = ALLOWED
> >>> 2024/01/10 11:55:49.849 kid1| 44,2| peer_select.cc(1181) handlePath:
> >>> never_direct = DENIED
> >>> 2024/01/10 11:55:49.849 kid1| 44,2| peer_select.cc(1182) handlePath:
> >>> timedout = 0
> >>> 2024/01/10 11:55:49.849 kid1| 14,7| ipcache.cc(253) forwardIp:
> >>> 216.239.38.120
> >>> 2024/01/10 11:55:49.849 kid1| 44,2| peer_select.cc(1174) handlePath:
> >>> PeerSelector300176 found conn2388485 local=0.0.0.0
> >>> remote=216.239.38.120:443 HIER_DIRECT flags=1, destination #2 for
> >>> forcesafesearch.google.com:443
> >>> 2024/01/10 11:55:49.849 kid1| 44,2| peer_select.cc(1180) handlePath:
> >>> always_direct = ALLOWED
> >>> 2024/01/10 11:55:49.849 kid1| 44,2| peer_select.cc(1181) handlePath:
> >>> never_direct = DENIED
> >>> 2024/01/10 11:55:49.849 kid1| 44,2| peer_select.cc(1182) handlePath:
> >>> timedout = 0
> >>> 2024/01/10 11:55:49.849 kid1| 14,7| ipcache.cc(236) finalCallback:
> >>> 0x12208e038
> >>> 2024/01/10 11:55:49.849 kid1| 44,2| peer_select.cc(479)
> >>> resolveSelected: PeerSelector300176 found all 2 destinations for
> >>> forcesafesearch.google.com:443
> >>> 2024/01/10 11:55:49.849 kid1| 44,2| peer_select.cc(480)
> >>> resolveSelected:    always_direct = ALLOWED
> >>> 2024/01/10 11:55:49.849 kid1| 44,2| peer_select.cc(481)
> >>> resolveSelected:     never_direct = DENIED
> >>> 2024/01/10 11:55:49.849 kid1| 44,2| peer_select.cc(482)
> >>> resolveSelected:         timedout = 0
> >>> 2024/01/10 11:55:49.849 kid1| 14,7| ipcache.cc(990) have:
> >>> [2001:4860:4802:32::78]:443 at 0 in [2001:4860:4802:32::78] #2/2-0
> >>> 2024/01/10 11:55:49.849 kid1| 14,2| ipcache.cc(1031) markAsBad:
> >>> [2001:4860:4802:32::78]:443 of forcesafesearch.google.com
> >>> 2024/01/10 11:55:49.855 kid1| 14,7| ipcache.cc(990) have:
> >>> 216.239.38.120:443 at 0 in [2001:4860:4802:32::78] #2/2-1
> >>> 2024/01/10 11:55:49.855 kid1| 14,2| ipcache.cc(1055) forgetMarking:
> >>> 216.239.38.120:443 of forcesafesearch.google.com
> >>> 2024/01/10 11:55:49.877 kid1| 14,3| Address.cc(389) lookupHostIP:
> >>> Given Non-IP 'forcesafesearch.google.com': hostname or servname not
> >>> provided or not known
> >>> 2024/01/10 11:55:49.877 kid1| 44,2| peer_select.cc(460)
> >>> resolveSelected: Find IP destination for:
> >>> forcesafesearch.google.com:443' via forcesafesearch.google.com
> >>> 2024/01/10 11:55:49.877 kid1| 14,4| ipcache.cc(617) nbgethostbyname:
> >>> forcesafesearch.google.com
> >>> 2024/01/10 11:55:49.877 kid1| 14,3| Address.cc(389) lookupHostIP:
> >>> Given Non-IP 'forcesafesearch.google.com': hostname or servname not
> >>> provided or not known
> >>> 2024/01/10 11:55:49.877 kid1| 14,4| ipcache.cc(657)
> >>> ipcache_nbgethostbyname_: ipcache_nbgethostbyname: HIT for
> >>> 'forcesafesearch.google.com'
> >>> 2024/01/10 11:55:49.877 kid1| 14,7| ipcache.cc(253) forwardIp:
> >>> [2001:4860:4802:32::78]
> >>> 2024/01/10 11:55:49.877 kid1| 44,2| peer_select.cc(1174) handlePath:
> >>> PeerSelector300177 found conn2388493 local=[::]
> >>> remote=[2001:4860:4802:32::78]:443 HIER_DIRECT flags=1, destination
> >>> #1 for forcesafesearch.google.com:443
> >>> 2024/01/10 11:55:49.877 kid1| 44,2| peer_select.cc(1180) handlePath:
> >>> always_direct = ALLOWED
> >>> 2024/01/10 11:55:49.877 kid1| 44,2| peer_select.cc(1181) handlePath:
> >>> never_direct = DENIED
> >>> 2024/01/10 11:55:49.877 kid1| 44,2| peer_select.cc(1182) handlePath:
> >>> timedout = 0
> >>> 2024/01/10 11:55:49.877 kid1| 14,7| ipcache.cc(253) forwardIp:
> >>> 216.239.38.120
> >>> 2024/01/10 11:55:49.877 kid1| 44,2| peer_select.cc(1174) handlePath:
> >>> PeerSelector300177 found conn2388494 local=0.0.0.0
> >>> remote=216.239.38.120:443 HIER_DIRECT flags=1, destination #2 for
> >>> forcesafesearch.google.com:443
> >>> 2024/01/10 11:55:49.877 kid1| 44,2| peer_select.cc(1180) handlePath:
> >>> always_direct = ALLOWED
> >>> 2024/01/10 11:55:49.877 kid1| 44,2| peer_select.cc(1181) handlePath:
> >>> never_direct = DENIED
> >>> 2024/01/10 11:55:49.877 kid1| 44,2| peer_select.cc(1182) handlePath:
> >>> timedout = 0
> >>> 2024/01/10 11:55:49.877 kid1| 14,7| ipcache.cc(236) finalCallback:
> >>> 0x12208e038
> >>> 2024/01/10 11:55:49.877 kid1| 44,2| peer_select.cc(479)
> >>> resolveSelected: PeerSelector300177 found all 2 destinations for
> >>> forcesafesearch.google.com:443
> >>> 2024/01/10 11:55:49.877 kid1| 44,2| peer_select.cc(480)
> >>> resolveSelected:    always_direct = ALLOWED
> >>> 2024/01/10 11:55:49.877 kid1| 44,2| peer_select.cc(481)
> >>> resolveSelected:     never_direct = DENIED
> >>> 2024/01/10 11:55:49.877 kid1| 44,2| peer_select.cc(482)
> >>> resolveSelected:         timedout = 0
> >>> 2024/01/10 11:55:49.877 kid1| 14,7| ipcache.cc(990) have:
> >>> [2001:4860:4802:32::78]:443 at 0 in [2001:4860:4802:32::78] #2/2-0
> >>> 2024/01/10 11:55:49.877 kid1| 14,2| ipcache.cc(1031) markAsBad:
> >>> [2001:4860:4802:32::78]:443 of forcesafesearch.google.com
> >>> 2024/01/10 11:55:49.882 kid1| 14,7| ipcache.cc(990) have:
> >>> 216.239.38.120:443 at 0 in [2001:4860:4802:32::78] #2/2-1
> >>> 2024/01/10 11:55:49.882 kid1| 14,2| ipcache.cc(1055) forgetMarking:
> >>> 216.239.38.120:443 of forcesafesearch.google.com
> >>>
> >>
> >> _______________________________________________
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> >> squid-users at lists.squid-cache.org
> >> https://lists.squid-cache.org/listinfo/squid-users
> >
> > _______________________________________________
> > squid-users mailing list
> > squid-users at lists.squid-cache.org
> > https://lists.squid-cache.org/listinfo/squid-users
> >
>
> --
> Dr. Stephen Borrill, Director and Solutions Architect
> Precedence Technologies Ltd              T: +44 (0) 1223 359 900
> Technology House, 36a Union Lane         E: sborrill at precedence.co.uk
> Cambridge, CB4 1QB, United Kingdom       W: http://www.precedence.co.uk/
> Limited company registered in England and Wales. Company number 3725626
>
> _______________________________________________
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>
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