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Ubuntu 14.04下进程管理工具supervisor安装

  supervisor的存在,主要是为了Nginx可以优雅的重启。作为一个进程管理工具,通过Supervisor启动其他进程,则其他进程都为其子进程。实现对特定的进程的守护(则其他进程不能设置为守护进程),在进程被挂起时,自动重启进程。


1.Supervisor安装

  可以安装在任何Unix系统,Ubuntu下可以通过easy_install supervisor进行安装。然后切换到root权限,通过echo_supervisord_conf > /etc/supervisord.conf创建配置文件,可以在其中更改所需要的配置。   修改配置,守护nginx进程,在/etc/supervisord.conf中添加以下信息:

[program:nginx]    
command=/usr/local/nginx/sbin/nginx    ;要执行的命令,即启动需要守护的进程
priority=1                             ;优先级
numprocs=1                             ;启动的进程数目
autostart=true                         ;supervisor启动的时候是否随着同时启动
autorestart=true                       ;supervisor程序crash的时候,这个进程会自动重启(很重要)


2.Supervisor守护Nginx测试

  • 指定配置文件,启动supervisord: sudo supervisord -c /etc/supervisord.conf,则根据配置文件的设置,nginx会被同时启动。
  • 通过sudo supervisorctl可以进入supervidor的命令行工具(可以代替接下来提到的Web界面进行管理,控制守护程序的start/restart/stop),或者查看其守护的进程的状态。
  • 查看守护进程状态: ps -le | grep supervisord
  • 查看Nginx进程状态: ps -le | grep nginx
  • 杀掉nginx进程: killall nginx
  • 结果发现,nginx被重启,且pid被切换


3. 通过Web界面管理进程以及查看进程状态

  通过配置文件的修改,supervisor通过web管理进程以及查看进程状态。如下所示:

[inet_http_server]         ; inet (TCP) server disabled by default
port=127.0.0.1:9001        ; (ip_address:port specifier, *:port for all iface)
username=admin             ; (default is no username (open server))
password=123               ; (default is no password (open server))

  其中port的设置表示允许任何ip进行访问,也可以指定单个ip可以访问。保存配置之后,supervisorctl reload重启,通过配置文件中配置的127.0.0.1:9001,输入用户名密码,即可访问。

   可以将tornado的python业务处理程序也加入supervisord的守护进程中(参考nginx的方法,修改配置文件),则该业务处理程序也随着supervisord儿而启动,直接通过localhost可以访问对应的helloworld程序。如下图可以发现,supervisord的守护进程队列,包含了nginx一级tornado的进程。


4. supervidor开机自启动

  • sudo supervisorctl stop <name>可以停止一个进程,但是该进程还会重新启动;
  • 要停止supervisord,直接ps查找到其对应的pid,kill -9 pid即可,其中-9的意思是,传递给进程的信号量为9,即强制,尽快终止进程;因为supervisord是以守护进程形式启动,所以将其kill之后,nginx依然顺利运行;当将supervisord设置成非守护进程,将其kill后,则nginx也停止运行;
  • 注意启动supervisord的时候一定要使用root权限,因为该进程的启动会带动nginx进程的启动,而nginx进程有监听80端口的操作,必须root权限,否则supervisord守护的进程将无法启动;
  • 对于Ubuntu系统来说,参考http://blog.csdn.net/shanliangliuxing/article/details/15499891的方法,新建文件/etc/init.d/supervisord中,并将文章末尾的脚本复制进去,执行以下命令,即将supervisord设置成了开机自启动;
sudo chmod +x /etc/init.d/supervisord
sudo update-rc.d supervisord defaults
sudo service supervisord start


/etc/init.d/supervisord文件内容:

#! /bin/sh
### BEGIN INIT INFO
# Provides:          supervisord
# Required-Start:    $remote_fs
# Required-Stop:     $remote_fs
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: Example initscript
# Description:       This file should be used to construct scripts to be
#                    placed in /etc/init.d.
### END INIT INFO
 
# Author: Dan MacKinlay <danielm@phm.gov.au>
# Based on instructions by Bertrand Mathieu
# http://zebert.blogspot.com/2009/05/installing-django-solr-varnish-and.html
 
# Do NOT "set -e"
 
# PATH should only include /usr/* if it runs after the mountnfs.sh script
PATH=/sbin:/usr/sbin:/bin:/usr/bin
DESC="Description of the service"
NAME=supervisord
DAEMON=/usr/local/bin/supervisord
DAEMON_ARGS=""
PIDFILE=/tmp/$NAME.pid
SCRIPTNAME=/etc/init.d/$NAME
 
# Exit if the package is not installed
[ -x "$DAEMON" ] || exit 0
 
# Read configuration variable file if it is present
[ -r /etc/default/$NAME ] && . /etc/default/$NAME
 
# Load the VERBOSE setting and other rcS variables
. /lib/init/vars.sh
 
# Define LSB log_* functions.
# Depend on lsb-base (>= 3.0-6) to ensure that this file is present.
. /lib/lsb/init-functions
 
#
# Function that starts the daemon/service
#
do_start()
{
	# Return
	#   0 if daemon has been started
	#   1 if daemon was already running
	#   2 if daemon could not be started
	start-stop-daemon --start --quiet --pidfile $PIDFILE --exec $DAEMON --test > /dev/null \
		|| return 1
	start-stop-daemon --start --quiet --pidfile $PIDFILE --exec $DAEMON -- \
		$DAEMON_ARGS \
		|| return 2
	# Add code here, if necessary, that waits for the process to be ready
	# to handle requests from services started subsequently which depend
	# on this one.  As a last resort, sleep for some time.
}
 
#
# Function that stops the daemon/service
#
do_stop()
{
	# Return
	#   0 if daemon has been stopped
	#   1 if daemon was already stopped
	#   2 if daemon could not be stopped
	#   other if a failure occurred
	start-stop-daemon --stop --quiet --retry=TERM/30/KILL/5 --pidfile $PIDFILE --name $NAME
	RETVAL="$?"
	[ "$RETVAL" = 2 ] && return 2
	# Wait for children to finish too if this is a daemon that forks
	# and if the daemon is only ever run from this initscript.
	# If the above conditions are not satisfied then add some other code
	# that waits for the process to drop all resources that could be
	# needed by services started subsequently.  A last resort is to
	# sleep for some time.
	start-stop-daemon --stop --quiet --oknodo --retry=0/30/KILL/5 --exec $DAEMON
	[ "$?" = 2 ] && return 2
	# Many daemons don't delete their pidfiles when they exit.
	rm -f $PIDFILE
	return "$RETVAL"
}
 
#
# Function that sends a SIGHUP to the daemon/service
#
do_reload() {
	#
	# If the daemon can reload its configuration without
	# restarting (for example, when it is sent a SIGHUP),
	# then implement that here.
	#
	start-stop-daemon --stop --signal 1 --quiet --pidfile $PIDFILE --name $NAME
	return 0
}
 
case "$1" in
  start)
	[ "$VERBOSE" != no ] && log_daemon_msg "Starting $DESC" "$NAME"
	do_start
	case "$?" in
		0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;;
		2) [ "$VERBOSE" != no ] && log_end_msg 1 ;;
	esac
	;;
  stop)
	[ "$VERBOSE" != no ] && log_daemon_msg "Stopping $DESC" "$NAME"
	do_stop
	case "$?" in
		0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;;
		2) [ "$VERBOSE" != no ] && log_end_msg 1 ;;
	esac
	;;
  #reload|force-reload)
	#
	# If do_reload() is not implemented then leave this commented out
	# and leave 'force-reload' as an alias for 'restart'.
	#
	#log_daemon_msg "Reloading $DESC" "$NAME"
	#do_reload
	#log_end_msg $?
	#;;
  restart|force-reload)
	#
	# If the "reload" option is implemented then remove the
	# 'force-reload' alias
	#
	log_daemon_msg "Restarting $DESC" "$NAME"
	do_stop
	case "$?" in
	  0|1)
		do_start
		case "$?" in
			0) log_end_msg 0 ;;
			1) log_end_msg 1 ;; # Old process is still running
			*) log_end_msg 1 ;; # Failed to start
		esac
		;;
	  *)
	  	# Failed to stop
		log_end_msg 1
		;;
	esac
	;;
  *)
	#echo "Usage: $SCRIPTNAME {start|stop|restart|reload|force-reload}" >&2
	echo "Usage: $SCRIPTNAME {start|stop|restart|force-reload}" >&2
	exit 3
	;;
esac
Published 01 May 2015
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