Get job id on called method from job - ruby-on-rails

I'm trying to get the job which starts an action in this particular action.
Let me explain.
class MyClass
def go_for_it(delay = true)
if delay
delay(run_at: 2.minutes.from_now).go_for_it(false)
else
# How can I know if I was called by a DelayedJob AND if yes, which one ?
puts "I'll do it"
end
end
end
my_class = MyClass.new
my_class.delay(run_at: 2.minutes.from_now).go_for_it
My aim here is to make restrictions on jobs creation. I don't want go_for_it method called twice but this method can delay again itself according to some reasons. If I add those lines to go_for_it:
calling_method = caller_locations[0].label
job = Delayed::Job.where(queue: "my_queue").first
puts job.payload_object.id
# => id of MyClass if recorded
puts job.payload_object.method_name
# => :go_for_it
In the case of go_for_it delaying itself, these data are not enough because job variable can be itself and then it's not a second different call of got_for_it. It's just itself delayed again.
What I need to know here is which job call run or invoke_job on go_for_it method.

If I'm understanding well, you need to know which job is actually running.
You can use a custom job with a before hook to do an action before running the job, also you'll have totally access to job object at this moment.
Example :
class MyClassJob
def initialize(my_object: MyClass.new)
#my_object = my_object
end
def before(job)
binding.pry
another_job = Delayed::Job.where(queue: "my_queue").where('id <> ?', job.id)
end
def perform
#my_object.go_for_it
end
end
MyClassJob.new().delay.perform

Related

cancelling a sheduled Sidekiq job in Rails

Some Sidekiq jobs in my app are scheduled to change the state of a resource to cancelled unless a user responds within a certain timeframe. There is a lot of information about how to best accomplish this task, but none of it actually cancels the job.
To cancel a job, the code in the wiki says:
class MyWorker
include Sidekiq::Worker
def perform(thing_id)
return if cancelled?
thing = Thing.find thing_id
thing.renege!
end
def cancelled?
Sidekiq.redis {|c| c.exists("cancelled-#{jid}") }
end
def self.cancel!(jid)
Sidekiq.redis {|c| c.setex("cancelled-#{jid}", 86400, 1) }
end
end
Yet here it's suggested that I do something like
def perform(thing_id)
thing = Thing.find thing_id
while !cancel?(thing)
thing.ignore!
end
end
def cancel?(thing_id)
thing = Thing.find thing_id
thing.matched? || thing.passed?
end
What's confusing about this and similar code on the wiki is none of it actually cancels the job. The above example just performs an update on thing if cancelled? returns false (as it should), but doesn't cancel if and when it returns true in the future. It just fails with an aasm transition error message and gets sent to the RetrySet. Calling MyWorker.cancel! jid in model code throws an undefined variable error. How can I access that jid in the model? How can actually cancel or delete that specific job? Thanks!
# The wiki code
class MyWorker
include Sidekiq::Worker
def perform(thing_id)
return if cancelled?
# do actual work
end
def cancelled?
Sidekiq.redis {|c| c.exists("cancelled-#{jid}") }
end
def self.cancel!(jid)
Sidekiq.redis {|c| c.setex("cancelled-#{jid}", 86400, 1) }
end
end
# create job
jid = MyWorker.perform_async("foo")
# cancel job
MyWorker.cancel!(jid)
You can do this but it won't be efficient. It's a linear scan for find a scheduled job by JID.
require 'sidekiq/api'
Sidekiq::ScheduledSet.new.find_job(jid).try(:delete)
Alternatively your job can look to see if it's still relevant when it runs.
Ok, so turns out I had one question already answered. One of the code sets I included was a functionally similar version of the code from the wiki. The solution to the other question ("how can I access that jid in the model?") seems really obvious if you're not still new to programming, but basically: store the jid in a database column and then retrieve/update it whenever it's needed! Duh!

Passing instance variables into delayed job

I'm trying to use delayed_jobs (background workers) to process my incoming email.
class EmailProcessor
def initialize(email)
#raw_html = email.raw_html
#subject = email.subject
end
def process
do something with #raw_html & #subject
end
handle_asynchronously :process, :priority => 20
end
The problem is I can't pass instance variables (#raw_html & #subject) into delayed jobs. Delayed jobs requests that I save data into the model to be retrieved in the background task, but I would prefer to have a background worker complete the entire task (including saving the record).
Any thoughts?
Use delay to pass params to a method that you want to run in the background:
class EmailProcessor
def self.process(email)
# do something with the email
end
end
# Then somewhere down the line:
EmailProcessor.delay.process(email)

Can I call delayed_job with max attempts of 1?

I have a method that I run asynchronously
User.delay(queue: 'users').grab_third_party_info(user.id)
In case this fails, I want it to not retry. My default retries are 3, which I cannot change. I just want to have this only try once. The following doesn't seem to work:
User.delay(queue: 'users', attempts: 3).grab_third_party_info(user.id)
Any ideas?
This isn't my favorite solution, but if you need to use the delay method that you can set the attempts: to one less your max attempts. So in your case the following should work
User.delay(queue: 'users', attempts: 2).grab_third_party_info(user.id)
Better yet you could make it safer by using Delayed::Worker.max_attempts
User.delay(queue: 'users', attempts: Delayed::Worker.max_attempts-1).grab_third_party_info(user.id)
This would enter it into your delayed_jobs table as if it already ran twice so when it runs again it will be at the max attempts.
From https://github.com/collectiveidea/delayed_job#custom-jobs
To set a per-job max attempts that overrides the Delayed::Worker.max_attempts you can define a max_attempts method on the job
NewsletterJob = Struct.new(:text, :emails) do
def perform
emails.each { |e| NewsletterMailer.deliver_text_to_email(text, e) }
end
def max_attempts
3
end
end
Does this help you?
You have to use a Custom Job.
Just like #lazzi showed, you have to create a custom job in order to override the max_attempts.
As you can see in the README here, the only params that the .delay method take are:
priority
run_at
queue
And if you think about it, a value for max_attempts is not stored in the delayed_jobs table, only the attempts are stored, so there's no way for it to be persisted.
The only way to do it is to create a custom job that gets re-instantiated when the delayed job worker processes the job. It then reads the value from the max_attempts method and uses that to determine if the current attempts in the table record equals or exceeds the max_attempts value.
In your case, the simplest way to do it would be something like this:
# Inside your user.rb
class User < ApplicationRecord
FetchThirdPartyInfoJob = Struct.new( :user ) do
def perform
User.grab_third_party_info(user.id) # REFACTOR: Make this an instance method so you don't need to pass the User's id to it.
end
def queue_name
"users"
end
def max_attempts
3
end
end
end
Then run it wherever you need to by using enqueue, like this:
Delayed::Job.enqueue( User::FetchThirdPartyInfoJob.new( user ) )
I also added a little REFACTOR comment on your code because User.grab_third_party_info(user.id) looks to be incorrectly setup as a class method that you then pass the instance id to instead of just calling it directly on the user instance. I can't think of a reason why you would want this, but if there is, please leave it in the comments so we can all learn.

Persist job results with Resque / Rails

In my Rails app, I'm trying to take my working API calls and have them handled by background workers.
I have the following in app/jobs/api_request_job.rb:
class ApiRequestJob
def self.perform(params)
Query.new(params).start
end
end
The Query class is where the HTTParty requests are being executed (there are lots of methods for different query types with the same basic format as the parks method:
require 'ostruct'
class Query
include FourSquare
attr_reader :results,
:first_address,
:second_address,
:queries,
:radius
def initialize(params)
#results = OpenStruct.new
#queries = params["query"]
#first_address = params["first_address"]
#second_address = params["second_address"]
#radius = params["radius"].to_f
end
def start
queries.keys.each do |query|
results[query] = self.send(query)
end
results
end
def parks
category_id = "4bf58dd8d48988d163941735"
first_address_results = FourSquare.send_request(#first_address, radius_to_meters, category_id)["response"]["venues"]
second_address_results = FourSquare.send_request(#second_address, radius_to_meters, category_id)["response"]["venues"]
response = [first_address_results, second_address_results]
end
And, finally, the controller. Before trying to farm this action out to background workers, this line was working fine: #results = Query.new(params).start
class ComparisonsController < ApplicationController
attr_reader :first_address, :second_address
def new
end
def show
#first_address = Address.new(params["first_address"])
#second_address = Address.new(params["second_address"])
if #first_address.invalid?
flash[:notice] = #first_address.errors.full_messages
redirect_to :back
elsif Query.new(params).queries.nil?
flash[:notice] = "You must choose at least one criteria for your comparison."
redirect_to comparisons_new_path(request.params)
else
#queries = params["query"].keys
#results = Resque.enqueue(ApiRequestJob, params) # <-- this is where I'm stuck
end
end
end
I'm running redis, have resque installed, and am running the task/starting the workers. The current value being returned for #results is true instead of the hash of results I was need to get back. Is there a way to have the results of the Resque job persist and return data instead of true? What am I missing about how to get background workers to return the same type of data my regular api calls were returning?
Many thanks in advance!
The true you are receiving means the job was scheduled enqueued successfully. The worker will pick it up and run it on the background asynchronously, which means, not at same time as the thread that enqueued it. So there's no way to retrieve the returned value from the job.
If you need the value from that process, you have to run it from the controller without the worker. Also, you wouldn't gain anything from just pushing the work to be done by another process as the web process would have to wait for the response to then keep going anyway.
If you need that returned value right away and are doing this for performance reasons, then you could look into other forms of concurrency, like having another thread doing the request and then only grabbing the result when you need it on the view like:
class AsyncValue
def initialize(&block)
#thr = Thread.new(&block)
end
def value
#thr.join
end
end
on the controller
#results = AsyncValue.new { Query.new(params).start }
and on the view
<%= #results.value.each .... %>
but you'd still have to work around error handling which can get pretty complicated, but is doable.
Personally, I'd just make the request in place, but you know your domain better than me.

Ruby on Rails - Delayed job in model

I need to do a delayed job to count fbLikes in Model but I have the error report of "undefined send_later() method". Is there any way to do delayed job to my fb_likes function in model?
==============================Latest===================================================
This is my latest code in my project. Things still the same, fb_likes does not display likes count.
[Company.rb]-MODEL
require "delayed_job"
require "count_job.rb"
class Company < ActiveRecord::Base
before_save :fb_likes
def fb_likes
Delayed::Job.enqueue(CountJob.new(self.fbId))
end
end
[config/lib/count_job.rb]
class CountJob<Struct.new(:fbId)
def perform
uri = URI("http://graph.facebook.com/#{fbId}")
data = Net::HTTP.get(uri)
self.fbLikes = JSON.parse(data)['likes']
end
end
[controller]
def create
#company = Company.new(params[:company])
if #company.save!
flash[:success] = "New company successfully registered."
----and other more code----
Library files are not required by default.
Rename the job file to count_job.rb. Using camelCase for filenames is insane and will burn you in unpredictable ways.
Create an initializer and add require 'count_job.rb'
One way is to create a separate worker that will get queued, the run to fetch the updated Model and call its fb_likes method on it, but the method will need to be public. Or take the logic into the worker itself.

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