Ruby threading/forking with API (Sinatra)

Question

I am using Sinatra gem for my API. What I want to do is when request is received process it, return the response and start new long running task.

I am newbie to Ruby, I have read about Threading but not sure what is the best way to accomplish my task.

Here my sinatra endpoint

  post '/items' do
     # Processing data
     # Return response (body ...)
     # Start long running task
  end

I would be grateful for any advice or example.

unkmas · Accepted Answer · 2016-12-26T10:15:26.243

I believe that better way to do it - is to use background jobs. While your worker executes some long-running tasks, it is unavailable for new requests. With background jobs - they do the work, while your web-worker can work with new request.

You can have a look at most popular backgroung jobs gems for ruby as a starting point: resque, delayed_jobs, sidekiq

UPD: Implementation depends on chosen gem, but general scheme will be like this:

# Controller
post '/items' do
  # Processing data
  MyAwesomeJob.enqueue # here you put your job into queue
  head :ok # or whatever
end

In MyAwesomejob you implement your long-runnning task

Next, about Mongoid and background jobs. You should never use complex objects as job arguments. I don't know what kind of task you are implementing, but there is general answer - use simple objects.

For example, instead of using your User as argument, use user_id and then find it inside your job. If you will do it like that, you can use any DB without problems.

Thanks for answer, could you please provide example how it would look like in my case, I mean returning response and than adding background job or vice versa ? Thanks — , Dec 26 '16 at 08:21
And one more thing, I am using Mongoid to save objects how can I use it or pass the object to the Sidekiq ? — , Dec 26 '16 at 08:46

score 0 · Answer 2 · answered Jan 17 '17 at 05:50

Agree with unkmas.

There are two ways to do this. Threads or a background job gem like sidekiq.

Threads are perfectly fine if the processing times aren't that high and if you don't want to write code for the worker. But there is a strong possibility that you might run up too many threads if you don't use a threadpool or if you're expecting bursty http traffic.

The best way to do it is by using sidekiq or something similar. You could even have a job queue like beanstalkd in between and en-queue the job to it and return the response. You can have a worker reading from the queue and processing it later on.

Ruby threading/forking with API (Sinatra)

2 Answers2