Ruby on rails Heroku worker在激活时抛出错误？

我得到了一个简单而免费的heroku应用程序，其中我添加了redis/sidekiq，以便在后台发送邮件。我设置了所有设置，一旦启动worker，我会在循环中收到以下错误消息：

Error fetching job: ERR max number of clients reached
/app/vendor/bundle/ruby/2.2.0/gems/redis-3.2.2/lib/redis/client.rb:114:in `call'
/app/vendor/bundle/ruby/2.2.0/gems/redis-3.2.2/lib/redis/client.rb:95:in `block in connect'
/app/vendor/bundle/ruby/2.2.0/gems/redis-3.2.2/lib/redis/client.rb:280:in `with_reconnect'
/app/vendor/bundle/ruby/2.2.0/gems/redis-3.2.2/lib/redis/client.rb:93:in `connect'
/app/vendor/bundle/ruby/2.2.0/gems/redis-3.2.2/lib/redis/client.rb:351:in `ensure_connected'
/app/vendor/bundle/ruby/2.2.0/gems/redis-3.2.2/lib/redis/client.rb:208:in `block in process'
/app/vendor/bundle/ruby/2.2.0/gems/redis-3.2.2/lib/redis/client.rb:293:in `logging'
/app/vendor/bundle/ruby/2.2.0/gems/redis-3.2.2/lib/redis/client.rb:207:in `process'
/app/vendor/bundle/ruby/2.2.0/gems/redis-3.2.2/lib/redis/client.rb:113:in `call'
/app/vendor/bundle/ruby/2.2.0/gems/redis-3.2.2/lib/redis/client.rb:196:in `block in call_with_timeout'
/app/vendor/bundle/ruby/2.2.0/gems/redis-3.2.2/lib/redis/client.rb:267:in `with_socket_timeout'
/app/vendor/bundle/ruby/2.2.0/gems/redis-3.2.2/lib/redis/client.rb:195:in `call_with_timeout'
/app/vendor/bundle/ruby/2.2.0/gems/redis-3.2.2/lib/redis.rb:1097:in `block in _bpop'
/app/vendor/bundle/ruby/2.2.0/gems/redis-3.2.2/lib/redis.rb:57:in `block in synchronize'
/app/vendor/ruby-2.2.2/lib/ruby/2.2.0/monitor.rb:211:in `mon_synchronize'
/app/vendor/bundle/ruby/2.2.0/gems/redis-3.2.2/lib/redis.rb:57:in `synchronize'
/app/vendor/bundle/ruby/2.2.0/gems/redis-3.2.2/lib/redis.rb:1094:in `_bpop'
/app/vendor/bundle/ruby/2.2.0/gems/redis-3.2.2/lib/redis.rb:1139:in `brpop'
/app/vendor/bundle/ruby/2.2.0/gems/redis-namespace-1.5.2/lib/redis/namespace.rb:393:in `call_with_namespace'
/app/vendor/bundle/ruby/2.2.0/gems/redis-namespace-1.5.2/lib/redis/namespace.rb:290:in `method_missing'
/app/vendor/bundle/ruby/2.2.0/gems/sidekiq-4.0.1/lib/sidekiq/fetch.rb:35:in `block in retrieve_work'
/app/vendor/bundle/ruby/2.2.0/gems/sidekiq-4.0.1/lib/sidekiq.rb:84:in `block in redis'
/app/vendor/bundle/ruby/2.2.0/gems/connection_pool-2.2.0/lib/connection_pool.rb:64:in `block (2 levels) in with'
/app/vendor/bundle/ruby/2.2.0/gems/connection_pool-2.2.0/lib/connection_pool.rb:63:in `handle_interrupt'
/app/vendor/bundle/ruby/2.2.0/gems/connection_pool-2.2.0/lib/connection_pool.rb:63:in `block in with'
/app/vendor/bundle/ruby/2.2.0/gems/connection_pool-2.2.0/lib/connection_pool.rb:60:in `handle_interrupt'
/app/vendor/bundle/ruby/2.2.0/gems/connection_pool-2.2.0/lib/connection_pool.rb:60:in `with'
/app/vendor/bundle/ruby/2.2.0/gems/sidekiq-4.0.1/lib/sidekiq.rb:81:in `redis'
/app/vendor/bundle/ruby/2.2.0/gems/sidekiq-4.0.1/lib/sidekiq/fetch.rb:35:in `retrieve_work'
/app/vendor/bundle/ruby/2.2.0/gems/sidekiq-4.0.1/lib/sidekiq/processor.rb:85:in `get_one'
/app/vendor/bundle/ruby/2.2.0/gems/sidekiq-4.0.1/lib/sidekiq/processor.rb:95:in `fetch'
/app/vendor/bundle/ruby/2.2.0/gems/sidekiq-4.0.1/lib/sidekiq/processor.rb:78:in `process_one'
/app/vendor/bundle/ruby/2.2.0/gems/sidekiq-4.0.1/lib/sidekiq/processor.rb:67:in `run'
/app/vendor/bundle/ruby/2.2.0/gems/sidekiq-4.0.1/lib/sidekiq/util.rb:16:in `watchdog'
/app/vendor/bundle/ruby/2.2.0/gems/sidekiq-4.0.1/lib/sidekiq/util.rb:24:in `block in safe_thread'

sidekiq.yml：

---
:queues:
  - default
  - mailers

sidekiq.rb：

Sidekiq.configure_server do |config|
  config.redis = { :namespace => "mynamespace" }
end

Sidekiq.configure_client do |config|
  config.redis = { :namespace => "mynamespace" }
end

require "sidekiq/web"
Sidekiq::Web.app_url = "/"
Sidekiq::Web.use(Rack::Auth::Basic, "Application") do |username, password|
  username == ENV.fetch("SIDEKIQ_WEB_USERNAME") &&
  password == ENV.fetch("SIDEKIQ_WEB_PASSWORD")
end

---

有人知道这里怎么了吗？如果您需要有关配置文件或其他信息，请告诉我。

将

sidekiq.yml

更改为

---
:queues:
  - default
  - mailers
:concurrency: 5

---

成功了。由于某种原因，将

并发性设置为
9
并没有成功，即使heroku允许redis nano插件使用10个。
这是我找到的最佳解决方案。如果您使用的是免费heroku计划和免费redis nano计划。所有连接的总和必须小于等于10。若要确保这些连接的总和，请查看此博客文章

他解释了一切是如何加起来的

作者还有一个计算器，可以帮助计算特定服务器、sidekiq等的配置。它还可以告诉您需要添加信息的位置。
我也被困在这个问题上，希望它能节省一些时间：）
您已经达到了计划允许的最大Redis连接数：是的，但我如何才能阻止它发生<代码>并发性

似乎没有效果。