logs:
root@ubuntu:/var/discourse/shared/standalone/log/rails# tail -f production.log
Error connecting to Redis on localhost:6379 (Errno::ECONNREFUSED) subscribe failed, reconnecting in 1 second. Call stack ["/var/www/discourse/vendor/bundle/ruby/2.4.0/gems/redis-3.3.5/lib/redis/client.rb:345:in `rescue in establish_connection'", "/var/www/discourse/vendor/bundle/ruby/2.4.0/gems/redis-3.3.5/lib/redis/client.rb:331:in `establish_connection'", "/var/www/discourse/vendor/bundle/ruby/2.4.0/gems/redis-3.3.5/lib/redis/client.rb:101:in `block in connect'", "/var/www/discourse/vendor/bundle/ruby/2.4.0/gems/redis-3.3.5/lib/redis/client.rb:293:in `with_reconnect'", "/var/www/discourse/vendor/bundle/ruby/2.4.0/gems/redis-3.3.5/lib/redis/client.rb:100:in `connect'", "/var/www/discourse/vendor/bundle/ruby/2.4.0/gems/redis-3.3.5/lib/redis/client.rb:276:in `with_socket_timeout'", "/var/www/discourse/vendor/bundle/ruby/2.4.0/gems/redis-3.3.5/lib/redis/client.rb:133:in `call_loop'", "/var/www/discourse/vendor/bundle/ruby/2.4.0/gems/redis-3.3.5/lib/redis/subscribe.rb:43:in `subscription'", "/var/www/discourse/vendor/bundle/ruby/2.4.0/gems/redis-3.3.5/lib/redis/subscribe.rb:12:in `subscribe'", "/var/www/discourse/vendor/bundle/ruby/2.4.0/gems/redis-3.3.5/lib/redis.rb:2775:in `_subscription'", "/var/www/discourse/vendor/bundle/ruby/2.4.0/gems/redis-3.3.5/lib/redis.rb:2143:in `block in subscribe'", "/var/www/discourse/vendor/bundle/ruby/2.4.0/gems/redis-3.3.5/lib/redis.rb:58:in `block in synchronize'", "/usr/local/lib/ruby/2.4.0/monitor.rb:214:in `mon_synchronize'", "/var/www/discourse/vendor/bundle/ruby/2.4.0/gems/redis-3.3.5/lib/redis.rb:58:in `synchronize'", "/var/www/discourse/vendor/bundle/ruby/2.4.0/gems/redis-3.3.5/lib/redis.rb:2142:in `subscribe'", "/var/www/discourse/vendor/bundle/ruby/2.4.0/gems/message_bus-2.1.2/lib/message_bus/backends/redis.rb:336:in `global_subscribe'", "/var/www/discourse/vendor/bundle/ruby/2.4.0/gems/message_bus-2.1.2/lib/message_bus.rb:525:in `global_subscribe_thread'", "/var/www/discourse/vendor/bundle/ruby/2.4.0/gems/message_bus-2.1.2/lib/message_bus.rb:473:in `block in new_subscriber_thread'"]