Provided by: libminion-perl_7.05-1_all 
NAME
Minion - Job queue
SYNOPSIS
use Minion;
# Connect to backend
my $minion = Minion->new(Pg => 'postgresql://postgres@/test');
# Add tasks
$minion->add_task(something_slow => sub {
my ($job, @args) = @_;
sleep 5;
say 'This is a background worker process.';
});
# Enqueue jobs
$minion->enqueue(something_slow => ['foo', 'bar']);
$minion->enqueue(something_slow => [1, 2, 3] => {priority => 5});
# Perform jobs for testing
$minion->enqueue(something_slow => ['foo', 'bar']);
$minion->perform_jobs;
# Build more sophisticated workers
my $worker = $minion->repair->worker;
while (int rand 2) {
if (my $job = $worker->register->dequeue(5)) { $job->perform }
}
$worker->unregister;
DESCRIPTION
Minion is a job queue for the Mojolicious <http://mojolicious.org> real-time web
framework, with support for multiple named queues, priorities, delayed jobs, job
dependencies, job progress, job results, retries with backoff, rate limiting, unique jobs,
statistics, distributed workers, parallel processing, autoscaling, remote control,
resource leak protection and multiple backends (such as PostgreSQL
<http://www.postgresql.org>).
Job queues allow you to process time and/or computationally intensive tasks in background
processes, outside of the request/response lifecycle. Among those tasks you'll commonly
find image resizing, spam filtering, HTTP downloads, building tarballs, warming caches and
basically everything else you can imagine that's not super fast.
use Mojolicious::Lite;
plugin Minion => {Pg => 'postgresql://sri:s3cret@localhost/test'};
# Slow task
app->minion->add_task(poke_mojo => sub {
my $job = shift;
$job->app->ua->get('mojolicious.org');
$job->app->log->debug('We have poked mojolicious.org for a visitor');
});
# Perform job in a background worker process
get '/' => sub {
my $c = shift;
$c->minion->enqueue('poke_mojo');
$c->render(text => 'We will poke mojolicious.org for you soon.');
};
app->start;
Background worker processes are usually started with the command
Minion::Command::minion::worker, which becomes automatically available when an application
loads the plugin Mojolicious::Plugin::Minion.
$ ./myapp.pl minion worker
Jobs can be managed right from the command line with Minion::Command::minion::job.
$ ./myapp.pl minion job
To manage background worker processes with systemd, you can use a unit configuration file
like this.
[Unit]
Description=My Mojolicious application workers
After=postgresql.service
[Service]
Type=simple
ExecStart=/home/sri/myapp/myapp.pl minion worker -m production
KillMode=process
[Install]
WantedBy=multi-user.target
Every job can fail or succeed, but not get lost, the system is eventually consistent and
will preserve job results for as long as you like, depending on "remove_after". While
individual workers can fail in the middle of processing a job, the system will detect this
and ensure that no job is left in an uncertain state, depending on "missing_after".
GROWING
And as your application grows, you can move tasks into application specific plugins.
package MyApp::Task::PokeMojo;
use Mojo::Base 'Mojolicious::Plugin';
sub register {
my ($self, $app) = @_;
$app->minion->add_task(poke_mojo => sub {
my $job = shift;
$job->app->ua->get('mojolicious.org');
$job->app->log->debug('We have poked mojolicious.org for a visitor');
});
}
1;
Which are loaded like any other plugin from your application.
# Mojolicious
$app->plugin('MyApp::Task::PokeMojo');
# Mojolicious::Lite
plugin 'MyApp::Task::PokeMojo';
EXAMPLES
This distribution also contains a great example application you can use for inspiration.
The link checker <https://github.com/kraih/minion/tree/master/examples/linkcheck> will
show you how to integrate background jobs into well-structured Mojolicious applications.
EVENTS
Minion inherits all events from Mojo::EventEmitter and can emit the following new ones.
enqueue
$minion->on(enqueue => sub {
my ($minion, $id) = @_;
...
});
Emitted after a job has been enqueued, in the process that enqueued it.
$minion->on(enqueue => sub {
my ($minion, $id) = @_;
say "Job $id has been enqueued.";
});
worker
$minion->on(worker => sub {
my ($minion, $worker) = @_;
...
});
Emitted in the worker process after it has been created.
$minion->on(worker => sub {
my ($minion, $worker) = @_;
my $id = $worker->id;
say "Worker $$:$id started.";
});
ATTRIBUTES
Minion implements the following attributes.
app
my $app = $minion->app;
$minion = $minion->app(MyApp->new);
Application for job queue, defaults to a Mojo::HelloWorld object.
backend
my $backend = $minion->backend;
$minion = $minion->backend(Minion::Backend::Pg->new);
Backend, usually a Minion::Backend::Pg object.
backoff
my $cb = $minion->backoff;
$minion = $minion->backoff(sub {...});
A callback used to calculate the delay for automatically retried jobs, defaults to
"(retries ** 4) + 15" (15, 16, 31, 96, 271, 640...), which means that roughly 25 attempts
can be made in 21 days.
$minion->backoff(sub {
my $retries = shift;
return ($retries ** 4) + 15 + int(rand 30);
});
missing_after
my $after = $minion->missing_after;
$minion = $minion->missing_after(172800);
Amount of time in seconds after which workers without a heartbeat will be considered
missing and removed from the registry by "repair", defaults to 1800 (30 minutes).
remove_after
my $after = $minion->remove_after;
$minion = $minion->remove_after(86400);
Amount of time in seconds after which jobs that have reached the state "finished" and have
no unresolved dependencies will be removed automatically by "repair", defaults to 172800
(2 days).
tasks
my $tasks = $minion->tasks;
$minion = $minion->tasks({foo => sub {...}});
Registered tasks.
METHODS
Minion inherits all methods from Mojo::EventEmitter and implements the following new ones.
add_task
$minion = $minion->add_task(foo => sub {...});
Register a task.
# Job with result
$minion->add_task(add => sub {
my ($job, $first, $second) = @_;
$job->finish($first + $second);
});
my $id = $minion->enqueue(add => [1, 1]);
my $result = $minion->job($id)->info->{result};
enqueue
my $id = $minion->enqueue('foo');
my $id = $minion->enqueue(foo => [@args]);
my $id = $minion->enqueue(foo => [@args] => {priority => 1});
Enqueue a new job with "inactive" state. Arguments get serialized by the "backend" (often
with Mojo::JSON), so you shouldn't send objects and be careful with binary data, nested
data structures with hash and array references are fine though.
These options are currently available:
attempts
attempts => 25
Number of times performing this job will be attempted, with a delay based on "backoff"
after the first attempt, defaults to 1.
delay
delay => 10
Delay job for this many seconds (from now), defaults to 0.
notes
notes => {foo => 'bar', baz => [1, 2, 3]}
Hash reference with arbitrary metadata for this job that gets serialized by the
"backend" (often with Mojo::JSON), so you shouldn't send objects and be careful with
binary data, nested data structures with hash and array references are fine though.
parents
parents => [$id1, $id2, $id3]
One or more existing jobs this job depends on, and that need to have transitioned to the
state "finished" before it can be processed.
priority
priority => 5
Job priority, defaults to 0. Jobs with a higher priority get performed first.
queue
queue => 'important'
Queue to put job in, defaults to "default".
foreground
my $bool = $minion->foreground($id);
Retry job in "minion_foreground" queue, then perform it right away with a temporary worker
in this process, very useful for debugging.
job
my $job = $minion->job($id);
Get Minion::Job object without making any changes to the actual job or return "undef" if
job does not exist.
# Check job state
my $state = $minion->job($id)->info->{state};
# Get job metadata
my $progress = $minion->$job($id)->info->{notes}{progress};
# Get job result
my $result = $minion->job($id)->info->{result};
lock
my $bool = $minion->lock('foo', 3600);
my $bool = $minion->lock('foo', 3600, {limit => 20});
Try to acquire a named lock that will expire automatically after the given amount of time
in seconds. You can release the lock manually with "unlock" to limit concurrency, or let
it expire for rate limiting.
# Only one job should run at a time (unique job)
$minion->add_task(do_unique_stuff => sub {
my ($job, @args) = @_;
return $job->finish('Previous job is still active')
unless $minion->lock('fragile_backend_service', 7200);
...
$minion->unlock('fragile_backend_service');
});
# Only five jobs should run at a time and we wait for our turn
$minion->add_task(do_concurrent_stuff => sub {
my ($job, @args) = @_;
sleep 1 until $minion->lock('some_web_service', 60, {limit => 5});
...
$minion->unlock('some_web_service');
});
# Only a hundred jobs should run per hour and we try again later if necessary
$minion->add_task(do_rate_limited_stuff => sub {
my ($job, @args) = @_;
return $job->retry({delay => 3600})
unless $minion->lock('another_web_service', 3600, {limit => 100});
...
});
These options are currently available:
limit
limit => 20
Number of shared locks with the same name that can be active at the same time, defaults
to 1.
new
my $minion = Minion->new(Pg => 'postgresql://postgres@/test');
my $minion = Minion->new(Pg => Mojo::Pg->new);
Construct a new Minion object.
perform_jobs
$minion->perform_jobs;
$minion->perform_jobs({queues => ['important']});
Perform all jobs with a temporary worker, very useful for testing.
# Longer version
my $worker = $minion->worker;
while (my $job = $worker->register->dequeue(0)) { $job->perform }
$worker->unregister;
These options are currently available:
queues
queues => ['important']
One or more queues to dequeue jobs from, defaults to "default".
repair
$minion = $minion->repair;
Repair worker registry and job queue if necessary.
reset
$minion = $minion->reset;
Reset job queue.
stats
my $stats = $minion->stats;
Get statistics for jobs and workers.
# Check idle workers
my $idle = $minion->stats->{inactive_workers};
These fields are currently available:
active_jobs
active_jobs => 100
Number of jobs in "active" state.
active_workers
active_workers => 100
Number of workers that are currently processing a job.
delayed_jobs
delayed_jobs => 100
Number of jobs in "inactive" state that are scheduled to run at specific time in the
future or have unresolved dependencies. Note that this field is EXPERIMENTAL and might
change without warning!
enqueued_jobs
enqueued_jobs => 100000
Rough estimate of how many jobs have ever been enqueued. Note that this field is
EXPERIMENTAL and might change without warning!
failed_jobs
failed_jobs => 100
Number of jobs in "failed" state.
finished_jobs
finished_jobs => 100
Number of jobs in "finished" state.
inactive_jobs
inactive_jobs => 100
Number of jobs in "inactive" state.
inactive_workers
inactive_workers => 100
Number of workers that are currently not processing a job.
unlock
my $bool = $minion->unlock('foo');
Release a named lock that has been previously acquired with "lock".
worker
my $worker = $minion->worker;
Build Minion::Worker object.
REFERENCE
This is the class hierarchy of the Minion distribution.
• Minion
• Minion::Backend
• Minion::Backend::Pg
• Minion::Command::minion
• Minion::Command::minion::job
• Minion::Command::minion::worker
• Minion::Job
• Minion::Worker
• Mojolicious::Plugin::Minion
AUTHOR
Sebastian Riedel, "sri@cpan.org".
CREDITS
In alphabetical order:
Andrey Khozov
Brian Medley
Hubert "depesz" Lubaczewski
Joel Berger
Paul Williams
COPYRIGHT AND LICENSE
Copyright (C) 2014-2017, Sebastian Riedel and others.
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
<https://github.com/kraih/minion>, Mojolicious::Guides, <http://mojolicious.org>.