Question

I am using Resque to process some background jobs on a Rails application.

The thing is that clients can cancel this jobs, so:

• If the job is still on the queue: dequeue it

  Resque.dequeue(GitHub::Jobs::UpdateNetworkGraph, 'repo:135325')
  

• If the job has finished: do nothing

• If the job is running: ???

Is there a way to programmatically find the job and in case it is running tell it to stop immediatly? My main concern is to be sure that I kill the desired job, not the current one being processed as it could be a different one form the moment I ask if it is running until the moment I kill it.

Answer 1

I dont think that resque store the process id of the fork process, it does
log it though but I dont it store the process id of the child process forked

you can see over here in Line 139

With regard to your question of how extract the process id of the running resque job I think the way to do it inside your job itself using redis data-structure

so consider code below is your perform action for a job create using redis hash(running_process) and add the current process_id in it with the current timestamp

class MyJob
 @queue = :myjob

 def self.perform
   field = Time.now.to_i
   redis.hsetnx "running_process",field,Process.pid 
   ### Rest of the code



   #### when the code is about to finish 
   ##remove the finish process from the 
   redis.hdel "running_process",field
  end

Now you can get the list of all running process by simply querying redis “running_process” hash something like this

redis.hgetall "running_process"

Caveats over here If the resque job fail then the process id would never be clean’t from

the hash what ever you do just make sure you cross check the process id you collect

from the redis hash is actually a running resque job

Hope this help