开始/停止花费太多时间

Question 1

有一个名为shutdown_lifetime的参数。它的默认值是30秒。

因此，当 Squid 收到关闭请求时，它会等待至少 30 秒才终止。

$ grep -B 8 "# shutdown_lifetime" /etc/squid3/squid.conf 

#  TAG: shutdown_lifetime   time-units
#   When SIGTERM or SIGHUP is received, the cache is put into
#   "shutdown pending" mode until all active sockets are closed.
#   This value is the lifetime to set for all open descriptors
#   during shutdown mode.  Any active clients after this many
#   seconds will receive a 'timeout' message.
# Default:
# shutdown_lifetime 30 seconds

只需“取消注释”最后一行并设置更短的时间：

shutdown_lifetime 10 seconds

更多信息请参见下文。

http://www.squid-cache.org/Doc/config/shutdown_lifetime/

Answer

有一个名为shutdown_lifetime的参数。它的默认值是30秒。

因此，当 Squid 收到关闭请求时，它会等待至少 30 秒才终止。

$ grep -B 8 "# shutdown_lifetime" /etc/squid3/squid.conf 

#  TAG: shutdown_lifetime   time-units
#   When SIGTERM or SIGHUP is received, the cache is put into
#   "shutdown pending" mode until all active sockets are closed.
#   This value is the lifetime to set for all open descriptors
#   during shutdown mode.  Any active clients after this many
#   seconds will receive a 'timeout' message.
# Default:
# shutdown_lifetime 30 seconds

只需“取消注释”最后一行并设置更短的时间：

shutdown_lifetime 10 seconds

更多信息请参见下文。

http://www.squid-cache.org/Doc/config/shutdown_lifetime/

Question 2

我为 Debian Wheezy 的 Squid 3.1.20-2.2 包找到了这个。

 $ vim /etc/init.d/squid3
 ...
 78
 79 stop () {
 80         PID=`cat $PIDFILE 2>/dev/null`
 81         start-stop-daemon --stop --quiet --pidfile $PIDFILE --exec $DAEMON
 82         #
 83         #       Now we have to wait until squid has _really_ stopped.
 84         #
 85         sleep 2
 86         if test -n "$PID" && kill -0 $PID 2>/dev/null
 87         then
 88                 log_action_begin_msg " Waiting"
 89                 cnt=0
 90                 while kill -0 $PID 2>/dev/null
 91                 do
 92                         cnt=`expr $cnt + 1`
 93                         if [ $cnt -gt 24 ]
 94                         then
 95                                 log_action_end_msg 1
 96                                 return 1
 97                         fi
 98                         sleep 5
 99                         log_action_cont_msg ""
100                 done
101                 log_action_end_msg 0
102                 return 0
103         else
104                 return 0
105         fi
106 }
107...

，该函数正在使用此无法识别的信号 (0)。

解决方法：在第 90 行，将信号更改为 SIGTERM 信号，例如 15。

 90                 while kill -15 $PID 2>/dev/null

然后，启动/停止 Squid 时将不会有任何延迟：

$ time /etc/init.d/squid3 stop
[ ok ] Stopping Squid HTTP Proxy 3.x: squid3.

real    0m2.036s
user    0m0.004s
sys     0m0.000s

$  time /etc/init.d/squid3 start
[ ok ] Starting Squid HTTP Proxy 3.x: squid3.

real    0m0.036s
user    0m0.004s
sys     0m0.004s

谨防：虽然它为服务提供了快速启动/停止，但是这种解决方法可能会破坏脚本的目的，因为脚本出于自身的原因使用信号 0。

Answer