Supervisor 介紹
Supervisord是用Python實現的一款非常實用的進程管理工具，類似於monit，monit和supervisord的一個比較大的差異是supervisord管理的進程必須由supervisord來啓動，monit可以管理已經在運行的程序；supervisord還要求管理的程序是非daemon程序，supervisord會幫你把它轉成daemon程序，因此如果用supervisord來管理nginx的話，必須在nginx的配置文件裏添加一行設置daemon off讓nginx以非daemon方式啓動。
官方文檔：http://supervisord.org/index.html
安裝
supervisor已經被收錄在epel的repo中，可以通過yum 直接安裝
配置
supervisor的配置文件爲:/etc/supervisord.conf 配置文件必須要有一個program配置項，這樣supervisord才知道哪個program需要被管理和監控。
[root@localhost ~]# cat /etc/supervisord.conf
[supervisord]
http_port=/var/tmp/supervisor.sock ; (default is to run a UNIX domain socket server)
;http_port=127.0.0.1:9001 ; (alternately, ip_address:port specifies AF_INET)
;sockchmod=0700 ; AF_UNIX socketmode (AF_INET ignore, default 0700)
;sockchown=nobody.nogroup ; AF_UNIX socket uid.gid owner (AF_INET ignores)
;umask=022 ; (process file creation umask;default 022)
logfile=/var/log/supervisor/supervisord.log ; (main log file;default $CWD/supervisord.log)
logfile_maxbytes=50MB ; (max main logfile bytes b4 rotation;default 50MB)
logfile_backups=10 ; (num of main logfile rotation backups;default 10)
loglevel=info ; (logging level;default info; others: debug,warn)
pidfile=/var/run/supervisord.pid ; (supervisord pidfile;default supervisord.pid)
nodaemon=false ; (start in foreground if true;default false)
minfds=1024 ; (min. avail startup file descriptors;default 1024)
minprocs=200 ; (min. avail process descriptors;default 200)
;nocleanup=true ; (don't clean up tempfiles at start;default false)
;http_username=user ; (default is no username (open system))
;http_password=123 ; (default is no password (open system))
;childlogdir=/tmp ; ('AUTO' child log dir, default $TEMP)
;user=chrism ; (default is current user, required if root)
;directory=/tmp ; (default is not to cd during start)
;environment=KEY=value ; (key value pairs to add to environment)
[supervisorctl]
serverurl=unix:///var/tmp/supervisor.sock ; use a unix:// URL for a unix socket
;serverurl=http://127.0.0.1:9001 ; use an http:// url to specify an inet socket
;username=chris ; should be same as http_username if set
;password=123 ; should be same as http_password if set
;prompt=mysupervisor ; cmd line prompt (default "supervisor")
; The below sample program section shows all possible program subsection values,
; create one or more 'real' program: sections to be able to control them under
; supervisor.
;[program:theprogramname]
;command=/bin/cat ; the program (relative uses PATH, can take args)
;priority=999 ; the relative start priority (default 999)
;autostart=true ; start at supervisord start (default: true)
;autorestart=true ; retstart at unexpected quit (default: true)
;startsecs=10 ; number of secs prog must stay running (def. 10)
;startretries=3 ; max # of serial start failures (default 3)
;exitcodes=0,2 ; 'expected' exit codes for process (default 0,2)
;stopsignal=QUIT ; signal used to kill process (default TERM)
;stopwaitsecs=10 ; max num secs to wait before SIGKILL (default 10)
;user=chrism ; setuid to this UNIX account to run the program
;log_stdout=true ; if true, log program stdout (default true)
;log_stderr=true ; if true, log program stderr (def false)
;logfile=/var/log/cat.log ; child log path, use NONE for none; default AUTO
;logfile_maxbytes=1MB ; max # logfile bytes b4 rotation (default 50MB)
;logfile_backups=10 ; # of logfile backups (default 10)啓動/停止 supervisorctl -c /etc/supervisord.conf start/stop XXX（XXX爲配置文件中，program處定義的名字）