Expeditor is a Ruby library that provides asynchronous execution and fault tolerance for microservices.
It is inspired by Netflix/Hystrix.
Expeditor currently supports Ruby 2.1 and higher.
Add this line to your application's Gemfile:
And then execute:
Or install it yourself as:
$ gem install expeditor
command1 = Expeditor::Command.new do ... end command2 = Expeditor::Command.new do ... end command1.start # non blocking command2.start # non blocking command1.get # wait until command1 execution is finished and get the result command2.get # wait until command2 execution is finished and get the result
asynchronous execution with dependencies
command1 = Expeditor::Command.new do ... end command2 = Expeditor::Command.new do ... end command3 = Expeditor::Command.new(dependencies: [command1, command2]) do |val1, val2| ... end command3.start # command1 and command2 are started concurrently, execution of command3 is wait until command1 and command2 are finished.
command = Expeditor::Command.new do # something that may be failed end # use fallback value if command is failed command_with_fallback = command.set_fallback do |e| log(e) default_value end command.start.get #=> error may be raised command_with_fallback.start.get #=> default_value if command is failed
If you set
Expeditor::Service#fallback_enabled, fallbacks do not occur. It is useful in test codes.
command = Expeditor::Command.new(timeout: 1) do ... end command.start command.get #=> Timeout::Error is raised if execution is timed out
command = Expeditor::Command.new do ... end # the option is completely same as retryable gem command.start_with_retry( tries: 3, sleep: 1, on: [StandardError], )
using thread pool
Expeditor use concurrent-ruby's executors as thread pool.
require 'concurrent' service = Expeditor::Service.new( executor: Concurrent::ThreadPoolExecutor.new( min_threads: 0, max_threads: 5, max_queue: 100, ) ) command = Expeditor::Command.new(service: service) do ... end service.current_status # => #<Expeditor::Status:0x007fdeeeb18468 @break=0, @dependency=0, @failure=0, @rejection=0, @success=0, @timeout=0> service.reset_status! # reset status in the service
service = Expeditor::Service.new( period: 10, # retention period of the service metrics (success, failure, timeout, ...) sleep: 1, # if once the circuit is opened, the circuit is still open until sleep time is passed even though failure rate is less than threshold threshold: 0.5, # if the failure rate is more than or equal to threshold, the circuit is opened non_break_count: 100 # if the total count of metrics is not more than non_break_count, the circuit is not opened even though failure rate is more than threshold ) command = Expeditor::Command.new(service: service) do ... end
current_thread option of
#start, command executes synchronous on current thread.
command1 = Expeditor::Command.new do ... end command2 = Expeditor::Command.new do ... end command1.start(current_thread: true) # blocking command2.start(current_thread: true) # blocking command1.get command2.get
After checking out the repo, run
bin/setup to install dependencies. Then, run
bin/console for an interactive prompt that will allow you to experiment.
To install this gem onto your local machine, run
bundle exec rake install. To release a new version, update the version number in
version.rb, and then run
bundle exec rake release to create a git tag for the version, push git commits and tags, and push the
.gem file to rubygems.org.
- Fork it ( https://github.com/cookpad/expeditor/fork )
- Create your feature branch (
git checkout -b my-new-feature)
- Commit your changes (
git commit -am 'Add some feature')
- Push to the branch (
git push origin my-new-feature)
- Create a new Pull Request