Useful, reliable distributed cron. Tired of your cron-like scheduler running key jobs twice? Would you like to be able to run your cron server on multiple machines and have it "just work"? Have we got the gem for you.
Zhong uses Redis to acquire exclusive locks on jobs, as well as recording when they last ran. This means that you can rest easy at night, knowing that your customers are getting their monthly Goat Fancy magazine subscriptions and you are rolling around in your piles of money without a care in the world.
🍊 Battle-tested at Instacart
Add this line to your application’s Gemfile:
gem 'zhong'Create a definition file, let's call it zhong.rb:
Zhong.redis = Redis.new(url: ENV["ZHONG_REDIS_URL"])
Zhong.schedule do
category "stuff" do
every 5.seconds, "foo" do
puts "foo"
end
every(1.minute, "running biz at 26th and 27th minute", at: ["**:26", "**:27"]) { puts "biz" }
every(1.week, "running baz on mon and wed", at: ["mon 22:45", "wed 23:13"]) { puts "baz" }
every(10.seconds, "boom every 10 seconds") { raise "fail" }
end
category "clutter" do
every(1.second, "compute", if: -> (t) { t.wday == 3 && rand < 0.5 }) do
puts "something happened on wednesday, maybe"
end
end
# note: callbacks that explicitly false will cause event to not run
on(:before_tick) do
puts "ding"
true
end
on(:after_tick) do
puts "dong"
end
on(:before_run) do |job, time|
puts "running #{job}"
true # can conditionally run a specific job
end
on(:after_run) do |job, time, ran|
puts "#{job} ran?: #{ran}"
end
on(:before_disable) do |job|
puts "#{job} is going to be disabled"
end
on(:after_disable) do |job|
puts "#{job} disabled"
end
on(:before_enable) do |job|
puts "#{job} is going to be enabled"
end
on(:after_enable) do |job|
puts "#{job} enabled"
end
error_handler do |e, job|
puts "dang, #{job} messed up: #{e}"
end
endThis file only describes what should be the schedule. Nothing will be executed until we actually run
Zhong.startafter describing the Zhong schedule.
You can run the cron process that will execute your code from the definitions
in the zhong.rb file by running:
zhong zhong.rbZhong comes with a web application that can display jobs, their last run and enable/disable them.
This is a Sinatra application that requires at least v2.0.0. You can add to your Gemfile
gem 'sinatra', "~>2.0"It can be protected by HTTP basic authentication by setting the following environment variables:
ZHONG_WEB_USERNAME: the usernameZHONG_WEB_PASSWORD: the password
You'll need to load the Zhong schedule to be able to see jobs in the web UI, typically
by requiring your zhong.rb definition file.
Load the Zhong schedule by creating an initializer at config/initializers/zhong.rb,
with the following content:
require "#{Rails.root}/zhong.rb"Add the following to your config/routes.rb:
require 'zhong/web'
Rails.application.routes.draw do
# Other routes here...
mount Zhong::Web, at: "/zhong"
endView the changelog.
Everyone is encouraged to help improve this project. Here are a few ways you can help:
- Report bugs
- Fix bugs and submit pull requests
- Write, clarify, or fix documentation
- Suggest or add new features
React
Typescript
Django
Laravel
Facebook
Microsoft
Google
Alibaba
D3
Tencent