Minion(3)

NAME
Minion - Job queue

SYNOPSIS
  use Minion;

  # Connect to backend
  my $minion = Minion->new(Pg => 'postgresql://postgres@/test');

  # Add tasks
  $minion->add_task(something_slow => sub ($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;

  # Start a worker to perform up to 12 jobs concurrently
  my $worker = $minion->worker;
  $worker->status->{jobs} = 12;
  $worker->run;

DESCRIPTION
Minion is a high performance job queue for the Perl programming language, with support for multiple named queues, priorities, high priority fast lane, delayed jobs, job dependencies, job progress, job results, retries with backoff, rate limiting, unique jobs, expiring jobs, statistics, distributed workers, parallel processing, autoscaling, remote control, Mojolicious <https://mojolicious.org> admin ui, resource leak protection and multiple backends (such as PostgreSQL <https://www.postgresql.org>).

Job queues allow you to process time and/or computationally intensive tasks in background processes, outside of the request/response lifecycle of web applications. 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.

Take a look at our excellent documentation in Minion::Guide!

EXAMPLES
This distribution also contains a great example application you can use for inspiration. The link checker <https://github.com/mojolicious/minion/tree/main/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
  $minion->on(enqueue => sub ($minion, $id) {
    ...
  });

Emitted after a job has been enqueued, in the process that enqueued it.

  $minion->on(enqueue => sub ($minion, $id) {
    say "Job $id has been enqueued.";
  });

  worker
  $minion->on(worker => sub ($minion, $worker) {
    ...
  });

Emitted in the worker process after it has been created.

  $minion->on(worker => sub ($minion, $worker) {
    say "Worker $$ 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. Note that this attribute is weakened.

  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.

  $minion->backoff(sub ($retries) {
    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). It is not recommended to set this value below 2 days.

  stuck_after
  my $after = $minion->stuck_after;
  $minion   = $minion->stuck_after(86400);

Amount of time in seconds after which jobs that have not been processed will be considered stuck by "repair" and transition to the "failed" state, 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 {...});
  $minion = $minion->add_task(foo => 'MyApp::Task::Foo');

Register a task, which can be a closure or a custom Minion::Job subclass. Note that support for custom task classes is EXPERIMENTAL and might change without warning!

  # Job with result
  $minion->add_task(add => sub ($job, $first, $second) {
    $job->finish($first + $second);
  });
  my $id = $minion->enqueue(add => [1, 1]);
  my $result = $minion->job($id)->info->{result};

  broadcast
  my $bool = $minion->broadcast('some_command');
  my $bool = $minion->broadcast('some_command', [@args]);
  my $bool = $minion->broadcast('some_command', [@args], [$id1, $id2, $id3]);

Broadcast remote control command to one or more workers.

  # Broadcast "stop" command to all workers to kill job 10025
  $minion->broadcast('stop', [10025]);

  # Broadcast "kill" command to all workers to interrupt job 10026
  $minion->broadcast('kill', ['INT', 10026]);

  # Broadcast "jobs" command to pause worker 23
  $minion->broadcast('jobs', [0], [23]);

  class_for_task
  my $class = $minion->class_for_task('foo');

Return job class for task. Note that this method is EXPERIMENTAL and might change without warning!

  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.

expire
      expire => 300

    Job is valid for this many seconds (from now) before it expires.

lax
      lax => 1

    Existing jobs this job depends on may also have transitioned to the "failed" state to allow for it to be processed, defaults to "false". Note that this option is EXPERIMENTAL and might change without warning!

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. Priorities can be positive or negative, but should be in the range between 100 and "-100".

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.

  guard
  my $guard = $minion->guard('foo', 3600);
  my $guard = $minion->guard('foo', 3600, {limit => 20});

Same as "lock", but returns a scope guard object that automatically releases the lock as soon as the object is destroyed, or "undef" if aquiring the lock failed.

  # Only one job should run at a time (unique job)
  $minion->add_task(do_unique_stuff => sub ($job, @args) {
    return $job->finish('Previous job is still active')
      unless my $guard = $minion->guard('fragile_backend_service', 7200);
    ...
  });

  # Only five jobs should run at a time and we try again later if necessary
  $minion->add_task(do_concurrent_stuff => sub ($job, @args) {
    return $job->retry({delay => 30})
      unless my $guard = $minion->guard('some_web_service', 60, {limit => 5});
    ...
  });

  history
  my $history = $minion->history;

Get history information for job queue.

These fields are currently available:

daily
      daily => [{epoch => 12345, finished_jobs => 95, failed_jobs => 2}, ...]

    Hourly counts for processed jobs from the past day.

  is_locked
  my $bool = $minion->is_locked('foo');

Check if a lock with that name is currently active.

  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};

  jobs
  my $jobs = $minion->jobs;
  my $jobs = $minion->jobs({states => ['inactive']});

Return Minion::Iterator object to safely iterate through job information.

  # Iterate through jobs for two tasks
  my $jobs = $minion->jobs({tasks => ['foo', 'bar']});
  while (my $info = $jobs->next) {
    say "$info->{id}: $info->{state}";
  }

  # Remove all failed jobs from a named queue
  my $jobs = $minion->jobs({states => ['failed'], queues => ['unimportant']});
  while (my $info = $jobs->next) {
    $minion->job($info->{id})->remove;
  }

  # Count failed jobs for a task
  say $minion->jobs({states => ['failed'], tasks => ['foo']})->total;

These options are currently available:

ids
      ids => ['23', '24']

    List only jobs with these ids.

notes
      notes => ['foo', 'bar']

    List only jobs with one of these notes.

queues
      queues => ['important', 'unimportant']

    List only jobs in these queues.

states
      states => ['inactive', 'active']

    List only jobs in these states.

tasks
      tasks => ['foo', 'bar']

    List only jobs for these tasks.

These fields are currently available:

args
      args => ['foo', 'bar']

    Job arguments.

attempts
      attempts => 25

    Number of times performing this job will be attempted.

children
      children => ['10026', '10027', '10028']

    Jobs depending on this job.

created
      created => 784111777

    Epoch time job was created.

delayed
      delayed => 784111777

    Epoch time job was delayed to.

expires
      expires => 784111777

    Epoch time job is valid until before it expires.

finished
      finished => 784111777

    Epoch time job was finished.

id
      id => 10025

    Job id.

lax
      lax => 0

    Existing jobs this job depends on may also have failed to allow for it to be processed.

notes
      notes => {foo => 'bar', baz => [1, 2, 3]}

    Hash reference with arbitrary metadata for this job.

parents
      parents => ['10023', '10024', '10025']

    Jobs this job depends on.

priority
      priority => 3

    Job priority.

queue
      queue => 'important'

    Queue name.

result
      result => 'All went well!'

    Job result.

retried
      retried => 784111777

    Epoch time job has been retried.

retries
      retries => 3

    Number of times job has been retried.

started
      started => 784111777

    Epoch time job was started.

state
      state => 'inactive'

    Current job state, usually "active", "failed", "finished" or "inactive".

task
      task => 'foo'

    Task name.

time
      time => 78411177

    Server time.

worker
      worker => '154'

    Id of worker that is processing the job.

  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. For convenience you can also use "guard" to release the lock automatically, even if the job failed.

  # Only one job should run at a time (unique job)
  $minion->add_task(do_unique_stuff => sub ($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
  $minion->add_task(do_concurrent_stuff => sub ($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
  $minion->add_task(do_rate_limited_stuff => sub ($job, @args) {
    return $job->retry({delay => 3600})
      unless $minion->lock('another_web_service', 3600, {limit => 100});
    ...
  });

An expiration time of 0 can be used to check if a named lock could have been acquired without creating one.

  # Check if the lock "foo" could have been acquired
  say 'Lock could have been acquired' unless $minion->lock('foo', 0);

Or to simply check if a named lock already exists you can also use "is_locked".

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:

id
      id => '10023'

    Dequeue a specific job.

min_priority
      min_priority => 3

    Do not dequeue jobs with a lower priority.

queues
      queues => ['important']

    One or more queues to dequeue jobs from, defaults to "default".

  perform_jobs_in_foreground
  $minion->perform_jobs_in_foreground;
  $minion->perform_jobs_in_foreground({queues => ['important']});

Same as "perform_jobs", but all jobs are performed in the current process, without spawning new processes.

  repair
  $minion = $minion->repair;

Repair worker registry and job queue if necessary.

  reset
  $minion = $minion->reset({all => 1});

Reset job queue.

These options are currently available:

all
      all => 1

    Reset everything.

locks
      locks => 1

    Reset only locks.

  result_p
  my $promise = $minion->result_p($id);
  my $promise = $minion->result_p($id, {interval => 5});

Return a Mojo::Promise object for the result of a job. The state "finished" will result in the promise being "fullfilled", and the state "failed" in the promise being "rejected". This operation can be cancelled by resolving the promise manually at any time.

  # Enqueue job and receive the result at some point in the future
  my $id = $minion->enqueue('foo');
  $minion->result_p($id)->then(sub ($info) {
    my $result = ref $info ? $info->{result} : 'Job already removed';
    say "Finished: $result";
  })->catch(sub ($info) {
    say "Failed: $info->{result}";
  })->wait;

These options are currently available:

interval
      interval => 5

    Polling interval in seconds for checking if the state of the job has changed, defaults to 3.

  stats
  my $stats = $minion->stats;

Get statistics for the job queue.

  # 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_locks
      active_locks => 100

    Number of active named locks.

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.

enqueued_jobs
      enqueued_jobs => 100000

    Rough estimate of how many jobs have ever been enqueued.

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.

uptime
      uptime => 1000

    Uptime in seconds.

workers
      workers => 200;

    Number of registered workers.

  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. Note that this method should only be used to implement custom workers.

  # Use the standard worker with all its features
  my $worker = $minion->worker;
  $worker->status->{jobs} = 12;
  $worker->status->{queues} = ['important'];
  $worker->run;

  # Perform one job manually in a separate process
  my $worker = $minion->repair->worker->register;
  my $job    = $worker->dequeue(5);
  $job->perform;
  $worker->unregister;

  # Perform one job manually in this process
  my $worker = $minion->repair->worker->register;
  my $job    = $worker->dequeue(5);
  if (my $err = $job->execute) { $job->fail($err) }
  else                         { $job->finish }
  $worker->unregister;

  # Build a custom worker performing multiple jobs at the same time
  my %jobs;
  my $worker = $minion->repair->worker->register;
  do {
    for my $id (keys %jobs) {
      delete $jobs{$id} if $jobs{$id}->is_finished;
    }
    if (keys %jobs >= 4) { sleep 5 }
    else {
      my $job = $worker->dequeue(5);
      $jobs{$job->id} = $job->start if $job;
    }
  } while keys %jobs;
  $worker->unregister;

  workers
  my $workers = $minion->workers;
  my $workers = $minion->workers({ids => [2, 3]});

Return Minion::Iterator object to safely iterate through worker information.

  # Iterate through workers
  my $workers = $minion->workers;
  while (my $info = $workers->next) {
    say "$info->{id}: $info->{host}";
  }

These options are currently available:

ids
      ids => ['23', '24']

    List only workers with these ids.

These fields are currently available:

id
      id => 22

    Worker id.

host
      host => 'localhost'

    Worker host.

jobs
      jobs => ['10023', '10024', '10025', '10029']

    Ids of jobs the worker is currently processing.

notified
      notified => 784111777

    Epoch time worker sent the last heartbeat.

pid
      pid => 12345

    Process id of worker.

started
      started => 784111777

    Epoch time worker was started.

status
      status => {queues => ['default', 'important']}

    Hash reference with whatever status information the worker would like to share.

API
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::Iterator

•   Minion::Job

•   Minion::Worker

•   Mojolicious::Plugin::Minion

•   Mojolicious::Plugin::Minion::Admin

BUNDLED FILES
The Minion distribution includes a few files with different licenses that have been bundled for internal use.

  Minion Artwork
  Copyright (C) 2017, Sebastian Riedel.

Licensed under the CC-SA License, Version 4.0 <http://creativecommons.org/licenses/by-sa/4.0>.

  Bootstrap
  Copyright (C) 2011-2021 The Bootstrap Authors.

Licensed under the MIT License, <http://creativecommons.org/licenses/MIT>.

  D3.js
  Copyright (C) 2010-2016, Michael Bostock.

Licensed under the 3-Clause BSD License, <https://opensource.org/licenses/BSD-3-Clause>.

  epoch.js
  Copyright (C) 2014 Fastly, Inc.

Licensed under the MIT License, <http://creativecommons.org/licenses/MIT>.

  Font Awesome
  Copyright (C) Dave Gandy.

Licensed under the MIT License, <http://creativecommons.org/licenses/MIT>, and the SIL OFL 1.1, <http://scripts.sil.org/OFL>.

  moment.js
  Copyright (C) JS Foundation and other contributors.

Licensed under the MIT License, <http://creativecommons.org/licenses/MIT>.

AUTHORS

  Project Founder
Sebastian Riedel, "sri@cpan.org".

  Contributors
In alphabetical order:

    Andrey Khozov

    Andrii Nikitin

    Brian Medley

    Franz Skale

    Hubert "depesz" Lubaczewski

    Joel Berger

    Paul Williams

    Stefan Adams

COPYRIGHT AND LICENSE
Copyright (C) 2014-2023, 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/mojolicious/minion>, Minion::Guide, <https://minion.pm>, Mojolicious::Guides, <https://mojolicious.org>.