Is there a way to setup a callback in ROR that would trigger at a specific time?
Lets say I'm running a contest that expries at a certain time. Lets say Monday July 28th at 9:00. I'd like to set up an observer that ran a function at Monday July 28th at 9:00. Does rails have a method to do this?
There's a run_at field in Delayed Job. You have to have a worker process in the background always running and looking for jobs that a set to run, but if your application is doing this a lot, it might be easier than always writing new cron jobs.
So, you could have a method in your Contest model that gets called in a after_create callback that sets up a delayed job to send out an email to a random winner at the date that's specified.
If it's a one time, or very infrequent deal, though, I'll agree about using whenever
You'd be better off writing a ruby script that runs via crontab at the exact time you need it to.
I agree about crontab, but I like whenever. It has a nice integration into cron that you can store with your repo and it integrates nicely with capistrano.
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I need to implement user faced scheduler, like users have reports and might choose schedule when they want those reports being sent to them.
Requirements are quote complex, like there should be schedules like each 12 hours, each 30 minutes, each second day, at Fridays at 1am, last Sunday of the months etc.
Is there Rails solution for that our should I create it from the ground?
Thanks!
Most schedulers for rails and ruby depend on a static file. You can use a queuing system like Delayed Job and make every job enqueue itself for next time after success. Or you can do a basic SheduledJob model which relates to the user, and stores the periodicity, next execution and last execution. And use a normal (frequent) scheduled task engine like clockwork to check for pending jobs.
I have an Ruby on Rails application which allows the user the execute certain jobs. These jobs are handled and executed by Sidekiq.
Now I want to give the user the possibility to schedule these jobs and like cron jobs allow them to be recurring on certain dates and time. The question is how to do this?
All Gems I have come across so far, like whenever, rufus, sidetiq or simple cron jobs only allow for the job to be hardcoded in a file. But what I want is a job that is set by the user and stored in the database.
The obvious way would be to create a cron that checks the database every minute for jobs that are due, executes them and sets the date and time to the next scheduled point. But this way also involved a lot of coding and seems to be a little complicated. Also I see it as a fake cron, because there is simply one cron job that always checks the database.
What I would really like is a solution where the user actually creates a cron job, but I didn't come across anything so far that does this. Also it doesn't have to be a Gem. A more simpler way of just doing this would be enough. And I'd like to think that I can't be the only one who wants to do something like this.
Hi I making a petition site. In my site i Have three types of petitions, every have self period. When period is passed it need to change petition status(integer value) automaticaly.
How to do this better? And wich time rails use on server, from my pc or from server?
I ask about because I need somehow to test it manually.
I'm noviece, so if it's possible help me with simpliest alghoritm. I don't need a pure safety and performance.
I would suggest implementing it as a rake task, that will run every day as a cron job and update the mentioned value if record matches the condition(exactly one year passed).
Using this way you avoid problems related to performance as the rake task launches in separate background and also you may run the task when your server isn't overloaded by other tasks, for example at night.
Following gem is useful to setup jobs by schedule https://github.com/javan/whenever
I'd like to make an email notification if SomeModel has not been updated for 2 hours.
What is the best way to implement it?
After a model has been saved, queue up a background job to run 2 hours from that time to send the email. When a new job is enqueued, remove any still-unrun jobs that are still on the queue.
resque-scheduler providers a pretty simple way of doing this, assuming you have redis up and running.
Personally I find the solution that #x1a4 proposes to be somewhat overkill. Given the relatively large window of 2 hours, I would just run a job periodically (say, once every 10-15 minutes), then search all Models for updated_at <= 2.hours.ago and send out the emails.
As for scheduling that job to run every 15 minutes, there are several options. You may use resque-scheduler, if you are using Resque. You may also use the standard system cron, but will incur some fairly substantial overhead starting Rails each time the job runs. I also have written a distributed scheduler gem (i.e. cron that can run on multiple machines, but act like it's only running on one), which uses Redis under the hood.
I have a rails app with a Location model, which has a rating, and a rating_count field. Now, I need to reset every Location's rating and rating_countattributes to 0 at a specific time everyday, lets say 12:00:00 UTC.
How would I accomplish this? I'm using the default sqlite3 databases.
The best option is to use cron. You can find tons of documentation out there!Although if you are running a Rails app you should check out whenever a pretty neat gem for managing cron jobs for your app!
The easiest thing is to write a rake task that does that job, and then use whatever scheduling system your host uses (cron).
An alternative is to use delayed_job which allows to push work to a background process. While delayed-job is not exactly suited for something like this, it is perfectably capable of doing this. If your rails process starts, you add a new job, to run at 12:00. And the running of the job reschedules the job.
The nice thing of delayed-job is that your code runs in the context of a rails-process, so you can use methods you already have. Also nice: jobs are stored in the database, so you can have an overview.
If you're on a *nix box, write a script to do the updates (eg. in PHP, or Perl) and simply add it to crontab. Check out cron.