[squid-users] Preparing for shutdown after xxx requests

[David]

So far Squid worked nice, but recently it shutdown again and again with:

Preparing for shutdown after xxx requests

has someone a hint what that causes squid to shutdown

Squid Cache: Version 3.5.19
on Archlinux

free -h:
                        total          used        free      shared 
Puffer/Cache cached
Mem:              7.7G        3.4G        672M        333M 3.7G        3.7G
Swap:             4.0G         41M        4.0G

2016/06/23 07:45:06| Set Current Directory to /var/cache/squid
2016/06/23 07:45:06 kid1| Preparing for shutdown after 967 requests
2016/06/23 07:45:06 kid1| Waiting 10 seconds for active connections to 
finish
2016/06/23 07:45:06 kid1| Closing HTTP port [::]:3128
2016/06/23 07:45:06 kid1| Set Current Directory to /var/cache/squid
2016/06/23 07:45:06 kid1| Starting Squid Cache version 3.5.19 for 
x86_64-pc-linux-gnu...
2016/06/23 07:45:06 kid1| Service Name: squid
2016/06/23 07:45:06 kid1| Process ID 17879
2016/06/23 07:45:06 kid1| Process Roles: worker
2016/06/23 07:45:06 kid1| With 1024 file descriptors available
2016/06/23 07:45:06 kid1| Initializing IP Cache...
2016/06/23 07:45:06 kid1| DNS Socket created at [::], FD 8
2016/06/23 07:45:06 kid1| DNS Socket created at 0.0.0.0, FD 9
2016/06/23 07:45:06 kid1| Adding nameserver 192.168.2.1 from 
/etc/resolv.conf
2016/06/23 07:45:06 kid1| Logfile: opening log 
daemon:/var/log/squid/access.log
2016/06/23 07:45:06 kid1| Logfile Daemon: opening log 
/var/log/squid/access.log
2016/06/23 07:45:06 kid1| Local cache digest enabled; rebuild/rewrite 
every 3600/3600 sec
2016/06/23 07:45:06 kid1| Store logging disabled
2016/06/23 07:45:06 kid1| Swap maxSize 61440000 + 3072000 KB, estimated 
4962461 objects
2016/06/23 07:45:06 kid1| Target number of buckets: 248123
2016/06/23 07:45:06 kid1| Using 262144 Store buckets
2016/06/23 07:45:06 kid1| Max Mem  size: 3072000 KB
2016/06/23 07:45:06 kid1| Max Swap size: 61440000 KB
2016/06/23 07:45:06 kid1| Rebuilding storage in /var/cache/squid (dirty log)
2016/06/23 07:45:06 kid1| Using Least Load store dir selection
2016/06/23 07:45:06 kid1| Set Current Directory to /var/cache/squid
2016/06/23 07:45:06 kid1| Finished loading MIME types and icons.
2016/06/23 07:45:06 kid1| HTCP Disabled.
2016/06/23 07:45:06 kid1| Squid plugin modules loaded: 0
2016/06/23 07:45:06 kid1| Adaptation support is off.
2016/06/23 07:45:06 kid1| Accepting HTTP Socket connections at 
local=[::]:3128 remote=[::] FD 14 flags=9
2016/06/23 07:45:07 kid1| Store rebuilding is 53.75% complete
2016/06/23 07:45:07 kid1| Done reading /var/cache/squid swaplog (7441 
entries)
2016/06/23 07:45:07 kid1| Finished rebuilding storage from disk.
2016/06/23 07:45:07 kid1|      7422 Entries scanned
2016/06/23 07:45:07 kid1|         0 Invalid entries.
2016/06/23 07:45:07 kid1|         0 With invalid flags.
2016/06/23 07:45:07 kid1|      7403 Objects loaded.
2016/06/23 07:45:07 kid1|         0 Objects expired.
2016/06/23 07:45:07 kid1|         0 Objects cancelled.
2016/06/23 07:45:07 kid1|        19 Duplicate URLs purged.
2016/06/23 07:45:07 kid1|         0 Swapfile clashes avoided.
2016/06/23 07:45:07 kid1|   Took 0.07 seconds (100137.97 objects/sec).
2016/06/23 07:45:07 kid1| Beginning Validation Procedure
2016/06/23 07:45:07 kid1|   Completed Validation Procedure
2016/06/23 07:45:07 kid1|   Validated 7403 Entries
2016/06/23 07:45:07 kid1|   store_swap_size = 490076.00 KB
2016/06/23 07:45:07 kid1| storeLateRelease: released 0 objects
2016/06/23 07:51:30| Set Current Directory to /var/cache/squid
2016/06/23 07:51:30 kid1| Preparing for shutdown after 28 requests
2016/06/23 07:51:30 kid1| Waiting 10 seconds for active connections to 
finish
2016/06/23 07:51:30 kid1| Closing HTTP port [::]:3128