I'm going to try again after my hiccup last night. The following is what I'm trying to find a solution to: After conditions in my controller are met, I need to run a job five minutes later. This is for a lottery website for a mmo. After a ticket is sold, based on specific conditions(player amount met, amount of lottery item met), players have five minutes to buy a tickets. After five minutes, I need to pick random unique ticket numbers and award winners tokens. Right now I run this manually. I'm looking for a solution that I can schedule in my controller to run five minutes later.
I have tried delayed_job which I cannot get to work locally on a mac. Ruby on Rails Delayed Job Local Wont Run I have tried iron.io paid solution with no luck.
Please offer suggestions with possible tutorials.
Thanks.
Sidekiq is great and you should try it first.
https://github.com/mperham/sidekiq
Mike Perham, the lead author, is a terrific programmer and he writes about comparisons among Sidekiq, Resque, Delayed Job.
Worth reading his blog post about it here:
http://www.mikeperham.com/2011/05/04/background-processing-vs-message-queueing/
Related
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.
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.
Currently, my Nokogiri script iterates through Google's SERPs until it finds the position of the target website. It does this for each keyword for each website that each user specifies (users are capped on amount of websites & keywords they can track).
Right now, it's run in a rake that's hard-scheduled every day and batches all scrapes at once by looping through all the websites in the database. But I'm concerned about scalability and swarming Google with a batch of requests.
I'd like a solution that scales and can run these scrapes over the course of the day. I'm not sure what kind of solution is available or what I'm really looking for.
Note: The amount of websites/keywords change from day to day as users add and delete their websites and keywords. I don't mean to make this question too superfluous, but is this the kind of thing Beanstalkd/Stalker (job queuing) can be used for?
You will have to balance two issues: Scalability for lots of users versus Google shutting you down for scaping in violation of their terms of use.
So your system will need to be able to distribute tasks to various different IPs to conceal your bulk scraping which suggests at least two levels of queuing. One to manage all the jobs and send them to each separate IP for subsequent searching and collecting results and queues on each separate machine to hold the requested searches until they are executed and the results returned.
I have no idea what Google's thresholds are (I am sure they don't advertise it) but exceeding them and getting cut off would obviously be devastating for what you are trying to do so your simple looping rake task is exactly what you shouldn't do after a certain number of users.
So yes, use a queue of some sort but realize that you probably have a different goal from the typical goal of a queue in that you want to deliberately delay jobs rather that offload word to avoid UI delays. So you will be seeking ways to slow down the queue rather than have it just execute job after job as they arrive in the queue.
So based on a cursory inspection of DelayedJob and BackgroundJobs it looks like DelayedJob has what you would need with the run_at attribute. But I am only speculating here and I am sure an expert would have more to say.
If I'm understanding correclty, it sounds like one of these tools might fit the bill:
Delayed_job: https://github.com/tobi/delayed_job
or
BackgroundJobs: http://codeforpeople.rubyforge.org/svn/bj/trunk/README
I've used both of them, and found them easy to work with.
There are definitely some background job libraries that might work.
delayed_job: https://github.com/collectiveidea/delayed_job (beware of the unmaintained branch from tobi!)
resque: https://github.com/defunkt/resque
However, you might think about just scheduling a Cron job that runs more times during the day, and processes less items per run.
SaaS solution: http://momentapp.com/ "Launch delayed jobs with scheduled http requests" - disclaimer a) in beta b) I am not affiliated with this service
This might seem like a FAQ on stackoverflow, but my requirements are a little different. While I have previously used BackgroundRB and DJ for running background processes in ruby, my requirement this time is to run some heavy analytics and mathematical computations on a huge set of data, and I need to do this only about the first 15 days of the month. Going by this, I am tempted to use cron and run a ruby script to accomplish this goal.
What I would like to know / understand is:
1 - Is using cron a good idea (cause I'm not a system admin, and so while I have basic idea of cron, I'm not overly confident of doing it perfectly)
2 - Can we somehow modify DJ to run only on the first 15 days of the month (with / without using cron), and then just stop and exit once all the jobs in the queue for the day are over (don't want it to ping the DB every time for a new job...whatever the jobs will be in the queue when DJ starts, that will be all).
I'm not sure if I have put the question in the right manner, but any help in this direction will be much appreciated.
Thanks
With cron's "minute hour day month dayofweek" time specification, 3:33am 1st through fifteenth of every month would be "33 3 1-15 * *"
Using cron would be really easy, and you have a lot of example and it is reliable.
Anyway here are few screen casts from Railcasts you may want to look at:
Starling and Workling
Custom Daemon
Yeah, why not? Go with cron. It's really well-tested in the wild, well suited for running periodical tasks and incredibly easy to use. You don't even need to learn the crontab syntax (although it's very easy) - just drop your script into /etc/cron.daily (this option might be available only on some Linux distros).
I'm not sure about the "only first fiteen days of the month" thing, but you can easily handle this condition inside your task, right?
EDIT:
Check out par's answer to see how to run the task only at a certain range of days.
I also had this requirement. I followed the "Automatic Periodic Tasks" recipe 75 in the Advanced Rails Recipes book. The recipe is written by David Bock. It has some code snippets and guidelines on how this can be achieved using cron and capistrano. However there is an unsolved (but mentioned) issue regarding users/permissions that has to be on the target machine. It is not really difficult to make it right, you just have to remember to do it and put it in you deployment capistrano scripts.
It seems that David Bock has continued to work on this and has now creaated a gem for use with cron: See his blog, and follow crondonkulous on github. Crondonkulous may very well take care of this user/permission thing and more, I haven't tried it.
Jarl