README.markdown

ResqueCleaner

github.com/ono/resque-cleaner

Description

ResqueCleaner is a Resque plugin which aims to help you to clean up failed jobs on Resque by:

• Showing stats of failed jobs
• Retrying failed jobs
• Removing failed jobs
• Filtering failed jobs

Installation

Install as a gem:

$ gem install resque-cleaner

Resque-Web integration

You have to load ResqueCleaner to enable the Cleaner tab.

    require 'resque-cleaner'

Console

Hopefully a situation of your failed jobs is simple enough to get figured out through the web interface. But, if not, a powerful filtering feature of ResqueCleaner may help you to understand what is going on with your console(irb).

Create Instance

    > cleaner = Resque::Plugins::ResqueCleaner.new

Show Stats

Shows stats of failed jobs grouped by date.

    > cleaner.stats_by_date
    2009/03/13:    6
    2009/11/13:   14
    2010/08/13:   22
         total:   42
    => {'2009/03/10' => 6, ...}

You could also group them by class.

    > cleaner.stats_by_class
         BadJob:    3
    HorribleJob:    7
          total:   10
    => {'BadJob' => 3, ...}

Or you could also group them by exception.

    > cleaner.stats_by_exception
	 RuntimeError:   35
    SyntaxError:    7
          total:   42
    => {'RuntimeError' => 35, ...}

You can get the ones filtered with a block: it targets only jobs which the block evaluates true.

e.g. Show stats only of jobs entered with some arguments:

    > cleaner.stats_by_date {|j| j["payload"]["args"].size > 0}
    2009/03/13:    3
    2009/11/13:    7
    2010/08/13:   11
         total:   22
    => {'2009/03/10' => 3, ...}

Retry(Requeue) Jobs

You can retry all failed jobs with this method.

    > cleaner.requeue

Of course, you can filter jobs with a block; it requeues only jobs which the block evaluates true.

e.g. Retry only jobs with some arguments:

    > cleaner.requeue {|j| j["payload"]["args"].size > 0}

The job hash is extended with a module which defines some useful methods. You can use it in the block.

e.g. Retry only jobs entered within a day:

    > cleaner.requeue {|j| j.after?(1.day.ago)}

e.g. Retry EmailJob entered with arguments within 3 days:

    > cleaner.requeue {|j| j.after?(3.days.ago) && j.klass?(EmailJob) && j["payload"]["args"].size>0}

See Helper Methods section bellow for more information.

NOTE: 1.day.ago is not in standard library. Using it for making explanation more understandable. It is equivalent to Time.now - 60*60*24*3.

Clear Jobs

You can clear all failed jobs with this method:

    > cleaner.clear

Like you can do with the retry method, the clear method takes a block. Here are some examples:

    > cleaner.clear {|j| j.retried?}
    => clears all jobs already retried and returns number of the jobs.

    > cleaner.clear {|j| j.queue?(:low) && j.before?('2010-10-10')}
    => clears all jobs entried in :low queue before 10th October, 2010.

    > cleaner.clear {|j| j.exception?("RuntimeError") && j.queue?(:low)}
    => clears all jobs raised RuntimeError and queued :low queue

Retry and Clear Jobs

You can retry(requeue) and clear failed jobs at the same time; just pass true as an argument.

e.g. Retry EmailJob and remove from failed jobs:

    > cleaner.requeue(true) {|j| j.klass?(EmailJob)}

Retry with other queue

You can requeue failed jobs into other queue. In this way, you can retry failed jobs without blocking jobs being entered by your service running in the live.

e.g. Retry failed jobs on :retry queue

    > cleaner.requeue(false, :queue => :retry)

Don't forget to launch resque worker for the queue.

% QUEUE=retry rake resque:work

Select Jobs

You can just select the jobs of course. Here are some examples:

    > cleaner.select {|j| j["payload"]["args"][0]=="Johonson"}
    > cleaner.select {|j| j.after?(2.days.ago)}
    > cleaner.select #=> returns all jobs

Helper Methods

Here is a list of methods a failed job retained through ResqueCleaner has:

retried?: returns true if the job has already been retried.
requeued?: alias of retried?.
before?(time): returns true if the job failed before the time.
after?(time): returns true if the job failed after the time.
klass?(klass_or_name): returns true if the class of job matches.
queue?(queue_name): returns true if the queue of job matches.
exception?(exception_name): returns true if the exception matches.

Failed Job

Here is a sample of failed jobs:

{"failed_at": "2009/03/13 00:00:00",
 "payload": {"args": ["Johnson"], "class": "BadJob"},
 "queue": "jobs",
 "worker": "localhost:7327:jobs,jobs2",
 "exception": "RuntimeError",
 "error": "Bad job, Johnson",
 "backtrace": 
  ["./test/test_helper.rb:108:in `perform'",
   "/opt/local/lib/ruby/gems/1.8/gems/resque-1.10.0/lib/resque/job.rb:133:in `perform'",
   "/opt/local/lib/ruby/gems/1.8/gems/resque-1.10.0/lib/resque/worker.rb:157:in `perform'",
   "/opt/local/lib/ruby/gems/1.8/gems/resque-1.10.0/lib/resque/worker.rb:124:in `work'",
   "....(omitted)....",
   "./test/test_helper.rb:41",
   "test/resque_cleaner_test.rb:3"]
}

Limiter

ResqueCleaner expects a disaster situation like a huge number of failed jobs are out there. Since ResqueCleaner's filter function is running on your application process but on your Redis, it would not respond ages if you try to deal with all of those jobs.

ResqueCleaner supposes recent jobs are more important than old jobs. Therefore ResqueCleaner deals with ONLY LAST X(default=1000) JOBS. In this way, you could avoid slow responses. You can change the number through limiter attribute.

Let's see how it works with an following example.

Sample Situation

• Number of failed jobs: 100,000

Default limiter is 1000 so that the limiter returns 1000 as a count.

    > cleaner.limiter.count
    => 1,000
    > cleaner.failure.count
    => 100,000

You could know if the limiter is on with on? method.

    > cleaner.limiter.on?
    => true

You can change the maximum number of the limiter with maximum attribute.

    > cleaner.limiter.maxmum = 3000
    => 3,000
    > cleaner.limiter.count
    => 3,000
    > cleaner.limiter.on?
    => true

With limiter, ResqueCleaner's filtering targets only the last X(3000 in this sample) failed jobs.

    > cleaner.select.size
    => 3,000

The clear_stale method deletes all jobs entered prior to the last X(3000 in this sample) failed jobs. This calls Redis API and no iteration occurs on Ruby application; it should be quick even if there are huge number of failed jobs.

    > cleaner.clear_stale
    > cleaner.failure.count
    => 3,000
    > cleaner.limiter.count
    => 3,000
    > cleaner.limiter.on?
    => false

Many Thanks!

To our Contributors