Based on business problems, redis was added to the project for caching and queuing. But now we just install and deploy on a single server, without purchasing other services like Ali Cloud, and without building master and slave. This leads to problems. If the redis process is accidentally blocked, then the business can not be carried out. This is not allowed. So when we think of what the process guards, we think of supervisor. supervisor is a client / server system that allows users to monitor and control many processes on the unix operating system. It can easily monitor, start, stop and restart one or more processes. Supervisor managed process, when a process is accidentally killed, supervisort will automatically pull it up after listening to the process died. It is very convenient to achieve the function of automatic recovery of the process, and no longer need to write shell scripts to control it.
1. Install supervisor
### Installation method:###
sudo su - #Switch to root yum install epel-release yum install -y supervisor ystemctl enable supervisord # Start-up self-start systemctl start supervisord # Start the supervisord service systemctl status supervisord # View supervisord service status ps -ef|grep supervisord # Check to see if supervisord process exists
2. Configure supervisor
Create the directory `mkdir/etc/supervisor d.d'required by supervisor/` Create a supervisor configuration file: `echo_supervisord_conf >/etc/supervisord.conf` Edit the supervisord.conf file: `vi/etc/supervisord.conf` The document reads as follows:
; Sample supervisor config file. ; ; For more information on the config file, please see: ; http://supervisord.org/configuration.html ; ; Notes: ; - Shell expansion ("~" or "$HOME") is not supported. Environment ; variables can be expanded using this syntax: "%(ENV_HOME)s". ; - Comments must have a leading space: "a=b ;comment" not "a=b;comment". [unix_http_server] file=/tmp/supervisor.sock ; (the path to the socket file) ;chmod=0700 ; socket file mode (default 0700) ;chown=nobody:nogroup ; socket file uid:gid owner ;username=user ; (default is no username (open server)) ;password=123 ; (default is no password (open server)) [inet_http_server] ; inet (TCP) server disabled by default port=127.0.0.1:9001 ; (ip_address:port specifier, *:port for all iface) Open Server Access ;username=user ; (default is no username (open server)) ;password=123 ; (default is no password (open server)) [supervisord] user = root logfile=/tmp/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 ; (log level;default info; others: debug,warn,trace) pidfile=/tmp/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) ;umask=022 ; (process file creation umask;default 022) ;user=chrism ; (default is current user, required if root) ;identifier=supervisor ; (supervisord identifier, default is 'supervisor') ;directory=/tmp ; (default is not to cd during start) ;nocleanup=true ; (don't clean up tempfiles at start;default false) ;childlogdir=/tmp ; ('AUTO' child log dir, default $TEMP) ;environment=KEY="value" ; (key value pairs to add to environment) ;strip_ansi=false ; (strip ansi escape codes in logs; def. false) ; the below section must remain in the config file for RPC ; (supervisorctl/web interface) to work, additional interfaces may be ; added by defining them in separate rpcinterface: sections [rpcinterface:supervisor] supervisor.rpcinterface_factory = supervisor.rpcinterface:make_main_rpcinterface [supervisorctl] serverurl=unix:///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") ;history_file=~/.sc_history ; use readline history if available ; 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) ;process_name=%(program_name)s ; process_name expr (default %(program_name)s) ;numprocs=1 ; number of processes copies to start (def 1) ;directory=/tmp ; directory to cwd to before exec (def no cwd) ;umask=022 ; umask for process (default None) ;priority=999 ; the relative start priority (default 999) ;autostart=true ; start at supervisord start (default: true) ;autorestart=unexpected ; whether/when to restart (default: unexpected) ;startsecs=1 ; number of secs prog must stay running (def. 1) ;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 b4 SIGKILL (default 10) ;stopasgroup=false ; send stop signal to the UNIX process group (default false) ;killasgroup=false ; SIGKILL the UNIX process group (def false) ;user=chrism ; setuid to this UNIX account to run the program ;redirect_stderr=true ; redirect proc stderr to stdout (default false) ;stdout_logfile=/a/path ; stdout log path, NONE for none; default AUTO ;stdout_logfile_maxbytes=1MB ; max # logfile bytes b4 rotation (default 50MB) ;stdout_logfile_backups=10 ; # of stdout logfile backups (default 10) ;stdout_capture_maxbytes=1MB ; number of bytes in 'capturemode' (default 0) ;stdout_events_enabled=false ; emit events on stdout writes (default false) ;stderr_logfile=/a/path ; stderr log path, NONE for none; default AUTO ;stderr_logfile_maxbytes=1MB ; max # logfile bytes b4 rotation (default 50MB) ;stderr_logfile_backups=10 ; # of stderr logfile backups (default 10) ;stderr_capture_maxbytes=1MB ; number of bytes in 'capturemode' (default 0) ;stderr_events_enabled=false ; emit events on stderr writes (default false) ;environment=A="1",B="2" ; process environment additions (def no adds) ;serverurl=AUTO ; override serverurl computation (childutils) ; The below sample eventlistener section shows all possible ; eventlistener subsection values, create one or more 'real' ; eventlistener: sections to be able to handle event notifications ; sent by supervisor. ;[eventlistener:theeventlistenername] ;command=/bin/eventlistener ; the program (relative uses PATH, can take args) ;process_name=%(program_name)s ; process_name expr (default %(program_name)s) ;numprocs=1 ; number of processes copies to start (def 1) ;events=EVENT ; event notif. types to subscribe to (req'd) ;buffer_size=10 ; event buffer queue size (default 10) ;directory=/tmp ; directory to cwd to before exec (def no cwd) ;umask=022 ; umask for process (default None) ;priority=-1 ; the relative start priority (default -1) ;autostart=true ; start at supervisord start (default: true) ;autorestart=unexpected ; whether/when to restart (default: unexpected) ;startsecs=1 ; number of secs prog must stay running (def. 1) ;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 b4 SIGKILL (default 10) ;stopasgroup=false ; send stop signal to the UNIX process group (default false) ;killasgroup=false ; SIGKILL the UNIX process group (def false) ;user=chrism ; setuid to this UNIX account to run the program ;redirect_stderr=true ; redirect proc stderr to stdout (default false) ;stdout_logfile=/a/path ; stdout log path, NONE for none; default AUTO ;stdout_logfile_maxbytes=1MB ; max # logfile bytes b4 rotation (default 50MB) ;stdout_logfile_backups=10 ; # of stdout logfile backups (default 10) ;stdout_events_enabled=false ; emit events on stdout writes (default false) ;stderr_logfile=/a/path ; stderr log path, NONE for none; default AUTO ;stderr_logfile_maxbytes=1MB ; max # logfile bytes b4 rotation (default 50MB) ;stderr_logfile_backups ; # of stderr logfile backups (default 10) ;stderr_events_enabled=false ; emit events on stderr writes (default false) ;environment=A="1",B="2" ; process environment additions ;serverurl=AUTO ; override serverurl computation (childutils) ; The below sample group section shows all possible group values, ; create one or more 'real' group: sections to create "heterogeneous" ; process groups. ;[group:thegroupname] ;programs=progname1,progname2 ; each refers to 'x' in [program:x] definitions ;priority=999 ; the relative start priority (default 999) ; The [include] section can just contain the "files" setting. This ; setting can list multiple files (separated by whitespace or ; newlines). It can also contain wildcards. The filenames are ; interpreted as relative to this file. Included files *cannot* ; include files themselves. [include] files = /etc/supervisord.d/conf.d/*.ini
Save exit and start supervisor supervisord-c/etc/supervisord.conf
Check if supervisor started successfully: ps-ef | grep supervisord
root 12285 1 0 Aug08 ? 00:00:14 /usr/bin/python /usr/bin/supervisord -c /etc/supervisord.conf root 31055 31005 0 12:41 pts/0 00:00:00 grep --color supervisord
At this point, the supervisor installation is complete
3.supervisor management
# systemctl stop supervisord # systemctl start supervisord # systemctl status supervisord # systemctl reload supervisord # systemctl restart supervisord
4.supervisor configuration guardian Redis
Create directories required by supervisor
mkdir /etc/supervisord.d/conf.d/ mkdir /etc/supervisord.d/logs/
Create the redis process daemon file: vi/etc/supervisord.d/conf.d/redis.ini
[program:redis] command=/usr/local/redis/bin/redis-server /usr/local/redis/conf/redis.conf autostart=true autorestart=true startsecs=3 daemonize=no stdout_logfile=/etc/supervisord.d/logs/redis.log;
The redis configuration file needs to be modified:
daemonize no supervised auto
Update file configuration supervisorctl update
Start the supervisor redis service: supervisorctl start redis
At this point, the supervisor installation configuration is over
Thank
Thank you for reading this, I hope this chapter can help you. Thank you