起因：

由于近期网站用户数量可能会激增。注册的验证邮件，订单的确认邮件都有可能让用户端卡主。就需要用异步任务来完成这些发件动作。

添加必备的gem

gem "sidekiq"
gem 'sidekiq-statistic'   #sidekiq查看任务完成情况
gem "capistrano-sidekiq", group: :development

完成sidekiq后端页面设定

• 在initializes/sidekiq.rb加入require 'sidekiq/web'和 require 'sidekiq-statistic'
• 添加路由设定
  

  require 'sidekiq/web'
  authenticate :user, lambda { |u| u.admin? } do
    mount Sidekiq::Web => '/sidekiq'
  end
  

  准备异步任务

• 修改rails异步任务设定, 在env/pro config.active_job.queue_adapter = :sidekiq
• 创建任务方法（这里要说的是，方法参数建议传id。原因很简单。）

Capistrano设定sidekiq

在capfile加入，sidekiq的顺序在bundler和passenger的下面，要不然会报错。

require "capistrano/bundler"
require "capistrano/rails/assets"
require "capistrano/rails/migrations"
require "capistrano/passenger"
require "capistrano/sidekiq"

在deploy.rb加入

set :pty, false
set :passenger_restart_with_touch, true

ubuntu安装redis

• sudo apt-get install redis-server

安装monit检测sidekiq任务状态，挂掉自动重启

• sudo apt-get install monit 安装monit
• sudo vi /etc/monit/monitrc
  打开四行注释
  

    set httpd port 2812 and
     use address localhost 
     allow localhost        
     allow admin:monit
  

• 创建sidekiq.conf设定文件 sudo vim /etc/monit/conf.d/sidekiq.conf加入如下代码
  

   check process sidekiq_yourprojectname_production0
   with pidfile "/home/apps/yourprojectname/shared/tmp/pids/sidekiq-0.pid"
   start program = "/bin/su - deploy -c 'cd /home/apps/yourprojectname/current && /usr/bin/env bundle exec sidekiq   --index 0 --pidfile /home/apps/yourprojectname/shared/tmp/pids/sidekiq-0.pid --environment production  --logfile /home/apps/yourprojectname/shared/log/sidekiq.log  -d'" with timeout 30 seconds
  
   stop program = "/bin/su - deploy -c 'cd /home/apps/yourprojectname/current && /usr/bin/env bundle exec sidekiqctl stop /home/apps/yourprojectname/shared/tmp/pids/sidekiq-0.pid'" with timeout 20 seconds
   group yourprojectname-sidekiq