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.
Add this line to your application’s Gemfile:
gem 'zhong'
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, "biz", at: ["**:26", "**:27"]) { puts "biz" }
every(1.week, "baz", at: ["mon 22:45", "wed 23:13"]) { puts "baz" }
every(10.seconds, "boom") { 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
end
Zhong comes with a web application that can display jobs, their last run and enable/disable them.
Add the following to your config/routes.rb:
require 'zhong/web'
mount Zhong::Web, at: "zhong"
View 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