[squid-users] killing RunCache

Hi list,

I´m experiencing something very strange, almost every 20 minutes y get
the message "Killing RunCache, pid XXXX" as you can see in this log:

2011/02/18 10:20:01| Killing RunCache, pid 23638
2011/02/18 10:20:01| Preparing for shutdown after 189767 requests
2011/02/18 10:20:01| Waiting 30 seconds for active connections to finish
2011/02/18 10:20:01| FD 183 Closing HTTP connection
2011/02/18 10:20:07| Starting Squid Cache version 3.0.STABLE25 for
i686-pc-linux-gnu...
2011/02/18 10:20:07| Process ID 5251
2011/02/18 10:20:07| With 1024 file descriptors available

--
2011/02/18 10:40:02| Killing RunCache, pid 5249
2011/02/18 10:40:02| Preparing for shutdown after 205359 requests
2011/02/18 10:40:02| Waiting 30 seconds for active connections to finish
2011/02/18 10:40:02| FD 183 Closing HTTP connection
2011/02/18 10:40:07| Starting Squid Cache version 3.0.STABLE25 for
i686-pc-linux-gnu...
2011/02/18 10:40:07| Process ID 19084
2011/02/18 10:40:07| With 1024 file descriptors available
--
2011/02/18 11:00:03| Killing RunCache, pid 19082
2011/02/18 11:00:03| Preparing for shutdown after 159779 requests
2011/02/18 11:00:03| Waiting 30 seconds for active connections to finish
2011/02/18 11:00:03| FD 183 Closing HTTP connection
2011/02/18 11:00:08| Starting Squid Cache version 3.0.STABLE25 for
i686-pc-linux-gnu...
2011/02/18 11:00:08| Process ID 1167
2011/02/18 11:00:08| With 1024 file descriptors available
--
2011/02/18 11:20:01| Killing RunCache, pid 1165
2011/02/18 11:20:01| Preparing for shutdown after 131488 requests
2011/02/18 11:20:01| Waiting 30 seconds for active connections to finish
2011/02/18 11:20:01| FD 183 Closing HTTP connection
2011/02/18 11:20:06| Starting Squid Cache version 3.0.STABLE25 for
i686-pc-linux-gnu...
2011/02/18 11:20:06| Process ID 14641
2011/02/18 11:20:06| With 1024 file descriptors available
--
2011/02/18 11:40:01| Killing RunCache, pid 14639
2011/02/18 11:40:01| Preparing for shutdown after 148627 requests
2011/02/18 11:40:01| Waiting 30 seconds for active connections to finish
2011/02/18 11:40:01| FD 183 Closing HTTP connection
2011/02/18 11:40:06| Starting Squid Cache version 3.0.STABLE25 for
i686-pc-linux-gnu...
2011/02/18 11:40:06| Process ID 27946
2011/02/18 11:40:06| With 1024 file descriptors available
Of course, it means squid restarts whit a few seconds of downtime. I'm
running Squid 3.0 Stable 25 over an opensuse 11.0 box.
This is the conf part of squid.conf that relates to the cache:
cache_mem 32 MB
cache_swap_low 90
cache_swap_high 95
maximum_object_size 4096 KB
minimum_object_size 0 KB
maximum_object_size_in_memory 1024 KB
ipcache_size 1024
ipcache_low 90
ipcache_high 95
cache_dir ufs /var/log/squid/cache 25000 42 256
Anyone knows what's going on?
Thanks a lot