Re: ip cache overflow

From: John Saunders <>
Date: Wed, 21 Aug 1996 13:07:40 +1000 (EST)

On Tue, 20 Aug 1996, Edward Moy wrote:

> I just got hundreds of lines like:
> [20/Aug/1996:13:11:13 -0700] ipcache.c:455: HELP!! IP Cache is overflowing!
> in my cache.log file. Since this is an active proxy server, I can't play
> around with to figure out the problem while disrupting service. Anyone
> know how to fix this problem?

I've also got what I think is an IP cache problem. I thought that negative
lookups would be cached for a limited time, so that squid could retry the
DNS lookup after a small wait. I have a negative time-to-live on a number
of cache entries that just keep getting more negative without the entry
being purged from the IP cache. So maybe the expiry functionality is dead
so you are getting overflows.

The relevant entries are: N -81838 0 N -90185 0 N -42009 0 N -74418 0

Three of these 4 are not valid and are the result of a user typo. The
problem I am concerned about is that the entry is
supposed to be my parent cache. However my IP link isn't up at the time
the daemons are started on the system. I was going to hack this by sending
a SIGHUP from the PPP ip-up script to reconfigure the cache when the link
(and hence DNS) is up. However SIGHUP doesn't work because the negative
DNS lookup never gets expired and the reconfiguration always fails.

Here is the log file after a SIGHUP:

[21/Aug/1996:13:01:46 +1000] main.c:249: reconfigure: SIGHUP received
[21/Aug/1996:13:01:46 +1000] main.c:250: Waiting 30 seconds for active connections to finish
[21/Aug/1996:13:01:46 +1000] main.c:336: FD 13 Closing HTTP connection
[21/Aug/1996:13:01:46 +1000] main.c:348: FD 14 Closing ICP connection
[21/Aug/1996:13:01:46 +1000] main.c:367: Restarting Squid Cache (version 1.0.7)...
[21/Aug/1996:13:01:46 +1000] neighbors.c:879: neighbors_init: Initializing Neighbors...
[21/Aug/1996:13:01:46 +1000] neighbors.c:894: Adding a parent:
[21/Aug/1996:13:01:46 +1000] ipcache.c:1046: ipcacheOpenServers: Starting 5 'dns_server' processes
[21/Aug/1996:13:01:46 +1000] main.c:290: Accepting HTTP connections on FD 13.
[21/Aug/1996:13:01:46 +1000] main.c:306: Accepting ICP connections on FD 14.
[21/Aug/1996:13:01:46 +1000] comm.c:946: getAddress: gethostbyname failure: (0) Unknown error
[21/Aug/1996:13:01:46 +1000] neighbors.c:412: WARNING!!: DNS lookup for '' failed!
[21/Aug/1996:13:01:46 +1000] neighbors.c:413: THIS NEIGHBOR WILL BE IGNORED.
[21/Aug/1996:13:01:46 +1000] main.c:379: Ready to serve requests.

Any suggestions.

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Received on Tue Aug 20 1996 - 20:10:12 MDT

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