Sidekiq on Heroku

redis-to-go.txt

# = General ==================================================================
port 10081
databases 1

loglevel notice
logfile /mnt/redis.330229.log

# = Security =================================================================
requirepass xxx


# = Limits ===================================================================
maxmemory 5242880
maxmemory-policy volatile-lru
maxmemory-samples 3

maxclients 10
timeout 150

# = Persistence ==============================================================
dir /home/redis/10081

rdbcompression yes
dbfilename dump.rdb

save 900 1
save 300 10
save 60 10000

# = Advanced Config ==========================================================
hash-max-ziplist-entries 64
hash-max-ziplist-value 512

list-max-ziplist-entries 512
list-max-ziplist-value 64

set-max-intset-entries 512

zset-max-ziplist-entries 128
zset-max-ziplist-value 64

activerehashing yes

# = LUA Scripting ============================================================
lua-time-limit 5000

# = Client Limits ============================================================
client-output-buffer-limit normal 0 0 0
client-output-buffer-limit slave 256mb 64mb 60
client-output-buffer-limit pubsub 32mb 8mb 60

sidekiq.yml

---
:concurrency: 1
:queues:
  - default
  - mailers

unicorn.rb

run_sidekiq_in_this_thread = ENV['SIDEKIQ_CONCURRENCY']

worker_processes Integer(ENV["WEB_CONCURRENCY"] || (run_sidekiq_in_this_thread ? 2 : 3))

timeout 15
preload_app true

before_fork do |server, worker|
  Signal.trap 'TERM' do
    puts 'Unicorn master intercepting TERM and sending myself QUIT instead'
    Process.kill 'QUIT', Process.pid
  end

  defined?(ActiveRecord::Base) and ActiveRecord::Base.connection.disconnect!
  
  if run_sidekiq_in_this_thread
    @resque_pid ||= spawn("bundle exec sidekiq -c 1 -C config/sidekiq.yml")
    Rails.logger.info('Spawned sidekiq #{@request_pid}')
  end
end

after_fork do |server, worker|
  Signal.trap 'TERM' do
    puts 'Unicorn worker intercepting TERM and doing nothing. Wait for master to send QUIT'
  end

  defined?(ActiveRecord::Base) and ActiveRecord::Base.establish_connection
end

z-error.txt

2015-02-11T17:51:49.458277+00:00 app[web.1]: Started GET "/sidekiq/queues" for 71.192.31.1 at 2015-02-11 17:51:49 +0000
2015-02-11T17:51:49.479546+00:00 app[web.1]: Redis::CommandError - ERR max number of clients reached:
2015-02-11T17:51:49.479552+00:00 app[web.1]: 	/app/vendor/bundle/ruby/2.2.0/gems/redis-3.2.0/lib/redis/client.rb:110:in `call'
2015-02-11T17:51:49.479554+00:00 app[web.1]: 	/app/vendor/bundle/ruby/2.2.0/gems/redis-3.2.0/lib/redis/client.rb:92:in `block in connect'
2015-02-11T17:51:49.479556+00:00 app[web.1]: 	/app/vendor/bundle/ruby/2.2.0/gems/redis-3.2.0/lib/redis/client.rb:273:in `with_reconnect'
2015-02-11T17:51:49.479557+00:00 app[web.1]: 	/app/vendor/bundle/ruby/2.2.0/gems/redis-3.2.0/lib/redis/client.rb:90:in `connect'
2015-02-11T17:51:49.479559+00:00 app[web.1]: 	/app/vendor/bundle/ruby/2.2.0/gems/redis-3.2.0/lib/redis/client.rb:337:in `ensure_connected'
2015-02-11T17:51:49.479560+00:00 app[web.1]: 	/app/vendor/bundle/ruby/2.2.0/gems/redis-3.2.0/lib/redis/client.rb:204:in `block in process'

The error seems to show up if you do not have a sidekiq process running with the -e production flag. Also, I forgot to set my SIDEKIQ_CONCURRENCY flag. Once I added those two flags, I now have Sidekiq running along RedisToGo nano on a single Heroku dyno!

Changed the command in unicorn.rb to:

bundle exec sidekiq -e production -c 1 -C config/sidekiq.yml