Minion::Backend(3)

NAME
Minion::Backend - Backend base class

SYNOPSIS
  package Minion::Backend::MyBackend;
  use Mojo::Base 'Minion::Backend';

  sub broadcast         {...}
  sub dequeue           {...}
  sub enqueue           {...}
  sub fail_job          {...}
  sub finish_job        {...}
  sub history           {...}
  sub list_jobs         {...}
  sub list_locks        {...}
  sub list_workers      {...}
  sub lock              {...}
  sub note              {...}
  sub receive           {...}
  sub register_worker   {...}
  sub remove_job        {...}
  sub repair            {...}
  sub reset             {...}
  sub retry_job         {...}
  sub stats             {...}
  sub unlock            {...}
  sub unregister_worker {...}

DESCRIPTION
Minion::Backend is an abstract base class for Minion backends, like Minion::Backend::Pg.

ATTRIBUTES
Minion::Backend implements the following attributes.

  minion
  my $minion = $backend->minion;
  $backend   = $backend->minion(Minion->new);

Minion object this backend belongs to. Note that this attribute is weakened.

METHODS
Minion::Backend inherits all methods from Mojo::Base and implements the following new ones.

  auto_retry_job
  my $bool = $backend->auto_retry_job($job_id, $retries, $attempts);

Automatically "retry" job with "backoff" in Minion if there are attempts left, used to implement backends like Minion::Backend::Pg.

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

Broadcast remote control command to one or more workers. Meant to be overloaded in a subclass.

  dequeue
  my $job_info = $backend->dequeue($worker_id, 0.5);
  my $job_info = $backend->dequeue($worker_id, 0.5, {queues => ['important']});

Wait a given amount of time in seconds for a job, dequeue it and transition from "inactive" to "active" state, or return "undef" if queues were empty. Meant to be overloaded in a subclass.

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".

These fields are currently available:

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

    Job arguments.

id
      id => '10023'

    Job ID.

retries
      retries => 3

    Number of times job has been retried.

task
      task => 'foo'

    Task name.

  enqueue
  my $job_id = $backend->enqueue('foo');
  my $job_id = $backend->enqueue(foo => [@args]);
  my $job_id = $backend->enqueue(foo => [@args] => {priority => 1});

Enqueue a new job with "inactive" state. Meant to be overloaded in a subclass.

These options are currently available:

attempts
      attempts => 25

    Number of times performing this job will be attempted, with a delay based on "backoff" in Minion 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.

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".

  fail_job
  my $bool = $backend->fail_job($job_id, $retries);
  my $bool = $backend->fail_job($job_id, $retries, 'Something went wrong!');
  my $bool = $backend->fail_job(
    $job_id, $retries, {whatever => 'Something went wrong!'});

Transition from "active" to "failed" state with or without a result, and if there are attempts remaining, transition back to "inactive" with a delay based on "backoff" in Minion. Meant to be overloaded in a subclass.

  finish_job
  my $bool = $backend->finish_job($job_id, $retries);
  my $bool = $backend->finish_job($job_id, $retries, 'All went well!');
  my $bool = $backend->finish_job(
    $job_id, $retries, {whatever => 'All went well!'});

Transition from "active" to "finished" state with or without a result. Meant to be overloaded in a subclass.

  history
  my $history = $backend->history;

Get history information for job queue. Meant to be overloaded in a subclass.

These fields are currently available:

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

    Hourly counts for processed jobs from the past day.

  list_jobs
  my $results = $backend->list_jobs($offset, $limit);
  my $results = $backend->list_jobs($offset, $limit, {states => ['inactive']});

Returns the information about jobs in batches. Meant to be overloaded in a subclass.

  # Get the total number of results (without limit)
  my $num = $backend->list_jobs(0, 100, {queues => ['important']})->{total};

  # Check job state
  my $results = $backend->list_jobs(0, 1, {ids => [$job_id]});
  my $state = $results->{jobs}[0]{state};

  # Get job result
  my $results = $backend->list_jobs(0, 1, {ids => [$job_id]});
  my $result  = $results->{jobs}[0]{result};

These options are currently available:

before
      before => 23

    List only jobs before this id.

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.

  list_locks
  my $results = $backend->list_locks($offset, $limit);
  my $results = $backend->list_locks($offset, $limit, {names => ['foo']});

Returns information about locks in batches. Meant to be overloaded in a subclass.

  # Get the total number of results (without limit)
  my $num = $backend->list_locks(0, 100, {names => ['bar']})->{total};

  # Check expiration time
  my $results = $backend->list_locks(0, 1, {names => ['foo']});
  my $expires = $results->{locks}[0]{expires};

These options are currently available:

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

    List only locks with these names.

These fields are currently available:

expires
      expires => 784111777

    Epoch time this lock will expire.

name
      name => 'foo'

    Lock name.

  list_workers
  my $results = $backend->list_workers($offset, $limit);
  my $results = $backend->list_workers($offset, $limit, {ids => [23]});

Returns information about workers in batches. Meant to be overloaded in a subclass.

  # Get the total number of results (without limit)
  my $num = $backend->list_workers(0, 100)->{total};

  # Check worker host
  my $results = $backend->list_workers(0, 1, {ids => [$worker_id]});
  my $host    = $results->{workers}[0]{host};

These options are currently available:

before
      before => 23

    List only workers before this id.

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.

  lock
  my $bool = $backend->lock('foo', 3600);
  my $bool = $backend->lock('foo', 3600, {limit => 20});

Try to acquire a named lock that will expire automatically after the given amount of time in seconds. An expiration time of 0 can be used to check if a named lock already exists without creating one. Meant to be overloaded in a subclass.

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.

  note
  my $bool = $backend->note($job_id, {mojo => 'rocks', minion => 'too'});

Change one or more metadata fields for a job. Setting a value to "undef" will remove the field. Meant to be overloaded in a subclass.

  receive
  my $commands = $backend->receive($worker_id);

Receive remote control commands for worker. Meant to be overloaded in a subclass.

  register_worker
  my $worker_id = $backend->register_worker;
  my $worker_id = $backend->register_worker($worker_id);
  my $worker_id = $backend->register_worker(
    $worker_id, {status => {queues => ['default', 'important']}});

Register worker or send heartbeat to show that this worker is still alive. Meant to be overloaded in a subclass.

These options are currently available:

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

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

  remove_job
  my $bool = $backend->remove_job($job_id);

Remove "failed", "finished" or "inactive" job from queue. Meant to be overloaded in a subclass.

  repair
  $backend->repair;

Repair worker registry and job queue if necessary. Meant to be overloaded in a subclass.

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

Reset job queue. Meant to be overloaded in a subclass.

These options are currently available:

all
      all => 1

    Reset everything.

locks
      locks => 1

    Reset only locks.

  retry_job
  my $bool = $backend->retry_job($job_id, $retries);
  my $bool = $backend->retry_job($job_id, $retries, {delay => 10});

Transition job back to "inactive" state, already "inactive" jobs may also be retried to change options. Meant to be overloaded in a subclass.

These options are currently available:

attempts
      attempts => 25

    Number of times performing this job will be attempted.

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!

parents
      parents => [$id1, $id2, $id3]

    Jobs this job depends on.

priority
      priority => 5

    Job priority.

queue
      queue => 'important'

    Queue to put job in.

  stats
  my $stats = $backend->stats;

Get statistics for the job queue. Meant to be overloaded in a subclass.

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 = $backend->unlock('foo');

Release a named lock. Meant to be overloaded in a subclass.

  unregister_worker
  $backend->unregister_worker($worker_id);

Unregister worker. Meant to be overloaded in a subclass.

SEE ALSO
Minion, Minion::Guide, <https://minion.pm>, Mojolicious::Guides, <https://mojolicious.org>.