I am using https://github.com/ssoroka/scheduler_daemon for my scheduled jobs, but I would like jobs immediately with a command (rather than waiting for the delay specified in the task).
I've tried using rails runner TaskName.run but the class can never be found (runner.rb:53:in 'eval': uninitialized constant TaskName (NameError)).
How can I run the scheduled tasks immediately?
If I guess correctly, you want to call one of the scheduled task directly.
If I were you, I'd ask to the author directly, via the channel he points at in the readme: https://github.com/ssoroka/scheduler_daemon/issues
If there is a way to do it, I'm sure the author will be glad to explain it in the readme as well.
Corollary question: for a one-time schedule, do you want your direct trigger to cancel the schedule?
You don't need the scheduler to run the task for you, just call the MyTask.new.run directly.
Related
I have a worker with one perform class. In the controller I am calling up that worker class. When I call it up with worker.perform.now I see in console that perform method is being executed as I want it.
How to schedule this callup in controller, to be performed every day at ten o'clock?
PS: When I call worker.perform_async it doesn't do anything.
PS: When I call worker.perform_async it doesn't do anything.
I guess, that you didn't start sidekiq server. Type sidekiq in console to start the server.
As it goes for scheduling sidekiq jobs to perform every period of time, there are several ways to do it.
The one recomended by the Sidekiq's author is to use CRON with Whenever gem. He even provide and example here: https://github.com/mperham/sidekiq/blob/master/examples/scheduling.rb
Other way is to use Sidekiq-cron gem. I've found it easier to setup, but it emulates CRON, that's why the first solution is more solid.
I have a ruby on rails app in which I'm trying to find a way to run some code every few seconds.
I've found lots of info and ideas using cron, or cron-like implementations, but these are only accurate down to the minute, and/or require external tools. I want to kick the task off every 15 seconds or so, and I want it to be entirely self contained within the application (if the app stops, the tasks stop, and no external setup).
This is being used for background generation of cache data. Every few seconds, the task will assemble some data, and then store it in a cache which gets used by all the client requests. The task is pretty slow, so it needs to run in the background and not block client requests.
I'm fairly new to ruby, but have a strong perl background, and the way I'd solve this there would be to create an interval timer & handler which forks, runs the code, and then exits when done.
It might be even nicer to just simulate a client request and have the rails controller fork itself. This way I could kick off the task by hitting the URI for it (though since the task will be running every few seconds, I doubt I'll ever need to, but might have future use). Though it would be trivial to just have the controller call whatever method is being called by the periodic task scheduler (once I have one).
I'd suggest the whenever gem https://github.com/javan/whenever
It allows you to specify a schedule like:
every 15.minutes do
MyClass.do_stuff
end
There's no scheduling cron jobs or monkeying with external services.
Generally speaking, there's no built in way that I know of to create a periodic task within the application. Rails is built on Rack and it expects to receive http requests, do something, and then return. So you just have to manage the periodic task externally yourself.
I think given the frequency that you need to run the task, a decent solution could be just to write yourself a simple rake task that loops forever, and to kick it off at the same time that you start your application, using something like Foreman. Foreman is often used like this to manage starting up/shutting down background workers along with their apps. On production, you may want to use something else to manage the processes, like Monit.
You can either write you own method, something like
class MyWorker
def self.work
#do you work
sleep 15
end
end
run it with rails runner MyWorker.work
There will be a separate process running in the background
Or you can use something like Resque, but that's a different approach. It works like that: something adds a task to the queue, meanwhile a worker is fetching whatever job it is in the queue, and tries to finish it.
So that depends on your own need.
I know it is an old question. But maybe for someone this answer could be helpful. There is a gem called crono.
Crono is a time-based background job scheduler daemon (just like Cron) for Ruby on Rails.
Crono is pure Ruby. It doesn't use Unix Cron and other platform-dependent things. So you can use it on all platforms supported by Ruby. It persists job states to your database using Active Record. You have full control of jobs performing process. It's Ruby, so you can understand and modify it to fit your needs.
The awesome thing with crono is that its code is self explained. In order to do a task periodically you can just do:
Crono.perform(YourJob).every 2.days
Maybe you can also do:
Crono.perform(YourJob).every 30.seconds
Anyway you really can do a lot of things. Another example could be:
Crono.perform(TestJob).every 1.week, on: :monday, at: "15:30"
I suggest this gem instead of whenever because whenever uses Unix Cron table which not always is available.
Throwing out a solution just because it looks somewhat elegant and answers the question without any extra gems. In my scenario I wanted to run some code, but only after all my Sidekiq workers were done doing their thing.
First I defined a method to check if any workers were working...
def workers_working?
workers = Sidekiq::Workers.new.map do |_process_id, _thread_id, work|
work
end
workers.size > 0
end
Then we just call the method with a loop which sleeps between calls.
sleep 5 while workers_working?
Use something like delayed job, and requeue it every so often?
Use thin or other server which uses eventmachine, then just use timers that are part of eventmachine. Example: in config/application.rb
EM.add_periodic_timer(2) do
do_this_every_2_sec
end
I am using collectiveidea for rails 2.3.8. I am creating array of delayed jobs to
perform some tasks, after some time I want to destroy all the delayed jobs which are running.
If anyone know the way to do this please help me.
You can invoke rake jobs:clear to delete all jobs in the queue.
In addition to the rake task, DelayedJob jobs are just a normal ActiveRecord model, so if you're in Ruby code you can do what you like with them:
Delayed::Job.destroy_all
Delayed::Job.delete_all
Delayed::Job.find(4).destroy
# etc.
Sounds like you've got a parent process that wants to timeout if its set of jobs doesn't complete within a certain time. Instead of hanging on to references to the jobs themselves, set a flag on a model that indicates that the process has given up. Jobs can check for that flag and short circuit if they're not needed anymore. (Your Job class should also wrap the contents of its #perform method in a timeout.)
It's almost always a bad idea to try to hang on to references to DJ objects as you seem to be suggesting.
I am using Resque to run a background process. This is how my background process works:
Scans through all the rows in an ActiveRecord model
Checks for a condition
Updates the row if the condition is met
And this needs to go on infinitely.
This is how I am trying to use Resque for my purpose, here's my worker class:
class ThumbnailMaker
#queue = :thumbnail_queue
def self.perform()
MyObj.check_thumbnails(root_url)
end
end
I understand the perform() method keeps a task in a queue, which is run periodically. In my case, I need a task that scans the whole table, so it runs for a longer time. Is it a good solution to my requirements?
On another note, I need the root url for my Rails application, which is easily obtained with the root_url in Rails Controller. But I need it in a class I have created, can you suggest me how I can get it here?
Resque is for queueing tasks to be run in the background; each item in the queue runs once and then is removed. What you want is more like a scheduled task--for example, a custom Rake task or other script that runs from time to time; there are many scheduling gems available for this kind of thing (wenever is very popular) or just use cron. There is a great RailsCasts episode about this very topic.
You might want to try putting your code in a rake task and running it periodically through a cron job. Resque/Redis seems a bit too much for your needs.
You may consider passing the root url in with as parameter if you are calling your class through your controller. Otherwise, you may want to set it as a ENV setting and configure each of your deployments accordingly.
I'm using Delayed Job to manage background work.
However I have some tasks that need to be executed at regular interval. Every hour, every day or every week for example.
For now, when I execute the task, I create a new one to be executed in one day/week/month.
However I don't really like it. If for any reason, the task isn't completely executed, we don't create the next one and we might lose the execution of the task.
How do you manage that kind of things (with delayed job) in your rails apps to be sure your regular tasks list remains correct ?
If you have access to Cron, I highly recommend Whenever
http://github.com/javan/whenever
You specify what you want to run and at what frequency in dead simple ruby, and whenever supplies rake tasks to convert this into a crontab and to update your system's crontab.
If you don't have access to frequent cron (like I don't, since we're on Heroku), then DJ is the way to go.
You have a couple options.
Do what you're doing. DJ will retry each task a certain number of times, so you have some leniency there
Put the code that creates the next DJ job in an ensure block, to make sure it gets created even after an exception or other bad event
Create another DJ that runs periodically, checks to make sure the appropriate DJs exist, and creates them if they don't. Of course, this is just as error prone as the other options, since the monitor and the actual DJ are both running in the same env, but it's something.
Is there any particular reason why you wouldn't use cron for this type of things?
Or maybe something more rubyish like rufus-scheduler, which is quite easy to use and very reliable.
If you don't need queuing, these tools are a way to go, I think.