I am working on rails 2 application where i need to send mail in background job.
I have Notifier model and from controller I call a model method to send mail.
I call that method Notifier.deliver_method_name(params) before using delayed job and after creating I use it Notifier.delay.deliver_method_name(params).
Now my question arise
1) Should I need to start the rake jobs:work to send mail in background in development and if yes should I run it every time I start server?
2) what do I need to do on production should I run rake jobs:work for the first time ?
3) Is that right if any error occurs then only there is a entry in delayed job if it is successful then there is no entry in delayed_job table.
I follow the below link
https://github.com/collectiveidea/delayed_job/tree/v2.0
Thanks :)
1) Should I need to start the rake jobs:work to send mail in background in development and if yes should I run it every time I start server?
Yes you have to start rake task separately.
Workers can be running on any computer, as long as they have access to the database and their clock is in sync. Keep in mind that each worker will check the database at least every 5 seconds.
2) what do I need to do on production should I run rake jobs:work for the first time ?
Yes you have to with RAILS_ENV=production script/delayed_job start But I suggest you stop and start this at every deployment to take changes done.
3) Is that right if any error occurs then only there is a entry in delayed job if it is successful then there is no entry in delayed_job table.
No it's completely depends on your configuration
# config/initializers/delayed_job_config.rb
Delayed::Worker.destroy_failed_jobs = false
Delayed::Worker.sleep_delay = 60
Delayed::Worker.max_attempts = 3
Delayed::Worker.max_run_time = 5.minutes
Related
I have a task that takes over 45 minutes. It runs successfully with
$ heroku run rake:sales
I also doublechecked my settings in scheduler based on this question. Everything looks fine.
In order to prevent run-away jobs, jobs that run longer than their frequency will be terminated. For example, a job that runs every 10 minutes will be terminated after running for 10 minutes.
What's happening is that your rake task is running for the first 10 minutes, but Heroku aborts it after that elapses. They suggest using a background job queue for long-running tasks.
Source:
https://devcenter.heroku.com/articles/scheduler#long-running-jobs
Apart from the long-running issue that #KKobayashi has alluded to, you may not have the correct rake file created for the scheduler to run:
Heroku Scheduler:
For Rails, the convention is to set up rake tasks. To create your
scheduled tasks in Rails, copy the code below into
lib/tasks/scheduler.rake and customize it to fit your needs
Have you tried putting your tasks into a a scheduler.rake file?
It could be that you're scheduling the task for an app other than the one you intend to schedule it for.
To check, open the scheduler (heroku addons:open scheduler) and check the url. If you see another app's name in the url, you need to add the scheduler addon again i.e.:
heroku addons:create scheduler:standard
Now open it again (heroku addons:open scheduler)
Hello I was trying to run a rake task every 5 minutes with this schedule code using the whenever gem
set :output, "#{path}/log/cron.log"
every 10.minutes do
rake "delete:old_offers"
end
But the code never execute. If I try to run my task with:
rake delete:old_offers
everything works great, so the problem is in the schedule file. Please I need your help to solve this issues.
I'm planning to execute this task every 60 days in my heroku app, so I could the schedule has to work also on heroku.
Thanks in advance.
UPDATE
Sorry guys, I have to set the environment to development like this
set :environment, 'development'
After you write your schedule, you need to actually update your crontab:
whenever --update-crontab
Simply running the whenever command by itself will only show you the schedule in cron format.
I created an app that uses the whenever gem. The gem creates cron jobs. I got it working locally but can't seem to get it working on heroku cedar. What's the command to do this?
running:
heroku run whenever --update-crontab job1
doesn't work
Short answer: use the scheduler add-on: http://addons.heroku.com/scheduler
Long answer: When you do heroku run, we
spin up a dyno
put your code on it
execute your command, wait for it to finish
throw the dyno away
Any changes you made to crontab would be immediately thrown away. Everything is ephemeral, you cannot edit files on heroku, just push new code.
You need to add Heroku Scheduler addon.
You can add it directly from your dashboard or using following commands:
install the add-on:
heroku addons:create scheduler:standard
Create a rake task in lib/tasks
# lib/tasks/scheduler.rake
task :send_reminders => :environment do
User.send_reminders
end
Schedule job
Visit Heroku Dashboard
Open your app
Select Scheduler from add-ons list
Click Add Job, enter a task and select frequency.
e.g. Add rake send_reminders, select "Daily" and "00:00" to send reminders every day at midnight.
The other answers specify you should use the Heroku Scheduler add-on, and it is able to run a background tasks indeed, but it doesn't support the flexibility of cron.
There's another add-on, called Cron To Go, that is able to run your jobs on one-off dynos with cron's flexibility. You can also specify a timezone for your job and get notifications (email or webhook) when job fail, succeed or start.
(Full disclosure - I work for the company that created and operates Cron To Go)
If you want to:
Use Heroku Scheduler
Run tasks every minute (not 10 min)
Don't care about dyno hours
This was my solution hack to run jobs every minute - assuming the task completes in under 60 seconds.
task start_my_service: :environment do
1.upto(9) do |iteration|
start_time = DateTime.now
Services::MyService.call
end_time = DateTime.now
wait_time = 60 - ((end_time - start_time) * 24 * 60 * 60).to_i
sleep wait_time if wait_time > 0
end
end
Heroku doesn't support cron jobs. And there are two drawbacks to the Heroku Scheduler :
you cannot choose an arbitrary interval or time at which to run jobs (it's either every 10 mins, 1 hour or daily).
your jobs are not defined in code, hence not in your versioning system and not easy to keep track of or modify.
Heroku does provide an alternative : custom clock processes. But the clock process requires its own dyno, and "Since dynos are restarted at least once a day some logic will need to exist on startup of the clock process to ensure that a job interval wasn’t skipped during the dyno restart".
Simple scheduler is a gem made specifically made for scheduling on Heroku, but seems a bit hackish.
I ended up using sidekiq-cron. Only drawback : if sidekiq is down right when a job is scheduled to run, the job won't run.
I followed the railscast which uses CollectiveIdea's fork. I'm not able to get it to work. I created a new file in my /lib folder and included this
class Device
def deliver
#my long running method
end
handle_asynchronously :deliver
end
device = Device.new
device.deliver
I do a script/delayed_job and that forks an app instance. Now,
There's no job activity going on. Nothing in the delayed_jobs table and nothing in the logs. Am I missing something here?
How do I set the interval for which the method should be run? (Ex every 30 seconds)
I'm testing this in the development mode (Rails 2.3.2), and soon will be moving this into production.
Thanks !
Do you see a process for the script/delayed_job that you ran? Do a ps aux | grep delayed_job and see if there is a process running.
AFAIK, you cannot set any time intervals using Delayed Job.
As a first step to diagnose the problem:
Stop your job workers
Launch a delayed job
Check whether it is present in the database.
I'm using Heroku and would like to have a script (on another server) called via cron that periodically requests an action on my Heroku app. This action will in turn run some processing that may take 1 or 2 minutes to complete. I believe Heroku has 30 second request limit, I was thinking could call a Rake task from my controller action instead.
Would this work? I'm curious if anyone has tried this yet.
Thanks.
The rake task would work as long as you don't use a HTTP request as proxy to initiate the task. In fact, if the task is forked from a HTTP Request, the timeout will be the same of the HTTP request.
You should a different method to start the task. Either a crontab (on Heroku side) or a Worker as good solutions.
I'd recommend using a background job on a worker for this. Your periodic process would then just have to start the worker and it wouldn't matter how long the process took.
I've just created a gem to solve exactly this problem. It allows you to queue up any rake task as a delayed_job e.g.
rake delay:db:seed
which will execute
rake db:seed
as a delayed_job. You can find it at http://rubygems.org/gems/delayed_task or http://blog.opsb.co.uk/long-running-rake-tasks-on-heroku.