Rails: Starting Sidekiq on Heroku

Question

I'm having a problem getting Sidekiq up and running on my Heroku deployed Rails app. I have my app working fine in development (and on Heroku without Sidekiq).

I created a Procfile with:

worker: bundle exec sidekiq

If I run heroku ps, the only process I see is web.1.

Should I see one for Sidekiq?

I do get an error:

Redis::CannotConnectError (Error connecting to Redis on localhost:6379) in my Heroku logs.

UPDATE: Found I probably needed heroku addons:add redistogo. Still not working. I feel I'm missing some basic configuration.

Is there something I need to do to get Redis up and running for my Heroku app?

I've been using Redis/Sidekiq for about a day, so this is new to me.

Thanks!

Greg

Solution 1

No you do not need any config with Heroku for Sidekiq, just add the RedisToGo plugin and you're on. Do not forget to attribute at least 1 worker to your app in your Heroku config.

Here is my default Procfile:

web: bundle exec thin start -p $PORT
worker: bundle exec sidekiq -c 5 -v

Solution 2

It's worth checking if the sidekiq process is really started with this command:

heroku ps

If there's no worker, then you might need to run this command:

heroku ps:scale worker+1

It turns out that there's a bug in the web UI in that some team members were not allowed to increase the number of workers from 0 to 1, even though the UI seemed to show that!

Solution 3

Starting with sidekiq version 3.0 there is an additional step, run heroku config:set REDIS_PROVIDER=REDISTOGO_URL in the console.

Here is the process I used for Rails 4:

In the console:

heroku addons:create redistogo
heroku config:set REDIS_PROVIDER=REDISTOGO_URL

In my Procfile I added:

worker: bundle exec sidekiq

In my gemfile.rb I added:

gem 'redis'

I added the following file, config/initializers/redis.rb:

uri = ENV["REDISTOGO_URL"] || "redis://localhost:6379/"
REDIS = Redis.new(:url => uri)

Here is the link to the sidekiq docs.

Solution 4

Complementing gdurelle answer:

You do need some config with Heroku for Sidekiq:

1) Have the Sidekiq and Redis gems installed (in gemfile and bundled), in my case:

Gemfile

gem 'redis', '~> 3.1'
gem 'sidekiq', '~> 2.7', '>= 2.7.1'

2) Add a worker, if you don't have any workers created locally I suggest you create at least one, just in case, use this:

rails g sidekiq:worker Hard # will create app/workers/hard_worker.rb

should create this:

app/workers/hard_worker.rb

class HardWorker
  include Sidekiq::Worker
  def perform(name, count)
    # do something
  end
end

3) Add the Redis add-on (in my case Heroku Redis):

heroku addons:create heroku-redis:hobby-dev

4) Add your redis.rb file, in my case:

config/initializers/redis.rb

$redis = Redis.new(url: ENV["REDIS_URL"])

5) Add Procfile or config/sidekiq.yml or both, here are mine:

Procfile

worker: bundle exec sidekiq -c 1 -q default -q mailers 

which you can create easier by pasting this in your terminal

echo "worker: bundle exec sidekiq -c 1 -q default -q mailers" > Procfile

config/sidekiq.yml

:concurrency: 1
:queues:
  - [mailers, 7]
  - [default, 5]

6) Most important part go here: and turn on the switch for your worker, click on the pencil and then turn on the missing switch. Things should be working fine now, have a great day!

Solution 5

What I found out is that you have to scale process manually like so:

heroku ps:scale worker+1

Makes no sense since my Procfile said:

web: bundle exec....
worker: bundle exec sidekiq

...and one would've expectd Heroku to start the worker automatically. In the end I didn't have to scale the web process...

Also, you might have problems with this line: worker: bundle exec sidekiq

Add flags for concurency:

worker: bundle exec sidekiq -c 5 -v

View more solutions

Comments

[Greg Rogers]

Yeah... it was the missing worker that was the last hangup for me. Thank you for the response! As an aside, why do you use 'thin'? Thanks!

[gdurelle]

old project, i'm gonna change for unicorn. if the answer help you click on the '^' arrow vote ;) ++

[Uri Klar]

Can you please explain the -c 5 -v options?

[gdurelle]

c : concurrency, v: verbose, p: port. You should read the documentation. really.

[Mark Gaensicke]

run bundle exec sidekiq -? to see a list of options with explanations

[Andrew Kostka]

@gdurelle The actual documentation doesn't show this in the deploy section. The documentation in general is very segmented, and it's easy to miss information.

[Clam]

I can only access the options help via bundle exec sidekiq -h Not sure if anybody has any further references to how to determine concurrency settings.

[Ryan Crews]

this. this was the answer to four hours of "why?!?!1!?1?!?!". thank you. (in fairness, I also needed to add the "worker: bundle exec sidekiq -c 5 -v", but you know, I did that four hours)

[Terra Ashley]

Edit #1 is no longer accurate.

[tambakoo]

@gdurelle what does the -c 5 -v do ?

[gdurelle]

@tambakoo Question already asked in comments above. This question is quite all maybe it has changed since : c is concurrency and v is verbose.

[mutantkeyboard]

I've had exactly the same problem with Heroku Redis instance. Couldn't turn on the switch on Heroku dashboard, so this solution worked for me.

[calyxofheld]

Turning on the worker switch is what did it for me, as I already had the worker defined in my Procfile. THANK YOU!

[Jose Paez]

I’m glad it helped, have a great day!

[BenKoshy]

for anyone reading this: for rails 6 in 2020 heroku recommends using puma.

[Francisco Quintero]

Gosh, I was looking like a mad man why Sidekiq wasn't running and the switch was off all the time. Thanks!

[Jose Paez]

Always glad to be of help, have a great day, happy coding!