NAME
Mojo::Server::DaemonControl - A Mojolicious daemon manager
SYNOPSIS
Commmand line
# Start the manager
$ mojodctl -l 'http://*:8080' -P /tmp/myapp.pid -w 4 /path/to/myapp.pl;
# Reload the manager
$ mojodctl -R -P /tmp/myapp.pid /path/to/myapp.pl;
# For more options
$ mojodctl --helpPerl API
use Mojo::Server::DaemonControl;
my $listen = Mojo::URL->new('http://*:8080');
my $dctl = Mojo::Server::DaemonControl->new(listen => [$listen], workers => 4);
$dctl->run('/path/to/my-mojo-app.pl');Mojolicious application
It is possible to use the "before_server_start" in Mojolicious hook to change server settings. The $app is also available, meaning the values can be read from a config file. See Mojo::Server::DaemonControl::Worker and Mojo::Server::Daemon for more information about what to tweak.
use Mojolicious::Lite -signatures;
app->hook(before_server_start => sub ($server, $app) {
if ($sever->isa('Mojo::Server::DaemonControl::Worker')) {
$server->inactivity_timeout(60);
$server->max_clients(100);
$server->max_requests(10);
}
});DESCRIPTION
Mojo::Server::DaemonControl is not a web server. Instead it manages one or more Mojo::Server::Daemon processes that can handle web requests. Each of these servers are started with SO_REUSEPORT enabled.
This means it is only supported on systems that support SO_REUSEPORT. It also does not support fork emulation. It should work on most modern Linux based systems though.
This server is an alternative to Mojo::Server::Hypnotoad where each of the workers handle long running (WebSocket) requests. The main difference is that a hot deploy will simply start new workers, instead of restarting the manager. This is useful if you need/want to deploy a new version of your server during the "graceful_timeout". Normally this is not something you would need, but in some cases where the graceful timeout and long running requests last for several hours or even days, then it might come in handy to let the old code run, while new processes are deployed.
Note that Mojo::Server::DaemonControl is currently EXPERIMENTAL and it has not been tested in production yet. Feedback is more than welcome.
ENVIRONMENT VARIABLES
Some environment variables can be set in systemd service files, while other can be useful to be read when initializing your web server.
MOJODCTL_CONTROL_CLASS
This environment variable will be set to Mojo::Server::DaemonControl::Worker inside the worker process.
MOJODCTL_GRACEFUL_TIMEOUT
Can be used to set the default value for "graceful_timeout".
MOJODCTL_HEARTBEAT_INTERVAL
Can be used to set the default value for "heartbeat_interval" and will be set to ensure a default value for "heartbeat_interval" in Mojo::Server::DaemonControl::Worker.
MOJODCTL_HEARTBEAT_TIMEOUT
Can be used to set the default value for "heartbeat_timeout".
MOJODCTL_LISTEN
Can be used to set the default value for "listen". The environment variable will be split on comma for multiple listen addresses.
MOJODCTL_LOG_FILE
By default the log will be written to STDERR. It is possible to set this environment variable to log to a file instead.
MOJODCTL_LOG_LEVEL
Can be set to debug, info, warn, error, fatal. Default log level is "info".
MOJODCTL_PID_FILE
Can be used to set a default value for "pid_file".
MOJODCTL_WORKERS
Can be used to set a default value for "workers".
SIGNALS
INT, TERM
Shut down server immediately.
QUIT
Shut down server gracefully.
TTIN
Increase worker pool by one.
TTOU
Decrease worker pool by one.
USR2
Will prevent existing workers from accepting new connections and eventually stop them, and start new workers in a fresh environment that handles the new connections. The manager process will remain the same.
$ mojodctl
|- myapp.pl-1647405707
|- myapp.pl-1647405707
|- myapp.pl-1647405707
|- myapp.pl
|- myapp.pl
'- myapp.plEXPERIMENTAL: The workers that waits to be stopped will have a timestamp appended to $0 to illustrate which is new and which is old.
ATTRIBUTES
Mojo::Server::DaemonControl inherits all attributes from Mojo::EventEmitter and implements the following ones.
graceful_timeout
$timeout = $dctl->graceful_timeout;
$dctl = $dctl->graceful_timeout(120);A worker will be forced stopped if it could not be gracefully stopped after this amount of time.
heartbeat_interval
$num = $dctl->heartbeat_interval;
$dctl = $dctl->heartbeat_interval(5);Heartbeat interval in seconds. This value is passed on to "heartbeat_interval" in Mojo::Server::DaemonControl::Worker.
heartbeat_timeout
$num = $dctl->heartbeat_timeout;
$dctl = $dctl->heartbeat_timeout(120);A worker will be stopped gracefully if a heartbeat has not been seen within this amount of time.
listen
$array_ref = $dctl->listen;
$dctl = $dctl->listen([Mojo::URL->new]);An array-ref of Mojo::URL objects for what to listen to. See "listen" in Mojo::Server::Daemon for supported values.
The reuse=1 query parameter will be added automatically before starting the Mojo::Server::Daemon sub process.
log
$log = $dctl->log;
$dctl = $dctl->log(Mojo::Log->new);A Mojo::Log object used for logging.
pid_file
$file = $dctl->pid_file;
$dctl = $dctl->pid_file(Mojo::File->new);A Mojo::File object with the path to the pid file.
Note that the PID file must end with ".pid"! Default path is "mojodctl.pid" in "tmpdir" in File::Spec.
workers
$int = $dctl->workers;
$dctl = $dctl->workers(4);Number of worker processes, defaults to 4. See "workers" in Mojo::Server::Prefork for more details.
worker_pipe
$socket = $dctl->worker_pipe;Holds a IO::Socket::UNIX object used to communicate with workers.
METHODS
Mojo::Server::DaemonControl inherits all methods from Mojo::EventEmitter and implements the following ones.
check_pid
$int = $dctl->check_pid;Returns the PID of the running process documented in "pid_file" or zero (0) if it is not running.
ensure_pid_file
$dctl->ensure_pid_file;Makes sure "pid_file" exists and contains the current PID.
reload
$int = $dctl->reload($app);Tries to reload a running instance by sending "USR2" to "pid_file".
run
$int = $dctl->run($app);Run the menager and wait for "SIGNALS". Note that $app is not loaded in the manager process, which means that each worker does not share any code or memory.
stop
$dctl->stop($signal);Used to stop the running manager and any "workers" with the $signal INT, QUIT or TERM (default).
AUTHOR
Jan Henning Thorsen
COPYRIGHT AND LICENSE
Copyright (C) Jan Henning Thorsen
This program is free software, you can redistribute it and/or modify it under the terms of the Artistic License version 2.0.
SEE ALSO
Mojo::Server::Daemon, Mojo::Server::Hypnotoad, Mojo::Server::DaemonControl::Worker.