hutch-schedule

Hutch Schedule

Add the schedule message function to Hutch.

See hutch-schedule-demo how to integration with rails.

Contents

• Hutch Schedule
  • Contents
  • Installation
  • Usage
  • Hutch::Enqueue
  • Hutch::Threshold
  • Error Retry
  • Rails
    • Work with Hutch it`s self
    • Work with ActiveJob
  • Limits
  • Contributing
  • License
  • TODO

Installation

Add this line to your application's Gemfile:

gem 'hutch-schedule'

And then execute:

$ bundle

Or install it yourself as:

$ gem install hutch-schedule

Usage

Use the code below to initialize the Hutch::Schedule

Hutch::Schedule.connect

They will do something below:

1. Declear an topic exchange called <hutch>.schedule just for routing message to delay_queue<5s>.
2. Declear an queue named <hutch>_delay_queue_<5s> and with some params:

• Set x-dead-letter-exchange: <hutch>: let queue republish message to default exchange.
• Set x-message-ttl: <30.days>: to avoid the queue is to large, because there is no consumer with this queue.

1. If ActiveJob is loaded. it will use ActiveJob::Base.descendants to register all ActiveJob class to one-job-per-consumer to Hutch::Consumer

Configurations

Name	Default Value	Description
worker_pool_size	20	Monkey patch the Hutch::Worker set the FixedThreadPool thread size(not the bunney ConsumerWorkPool size)
poller_interval	1	seconds of the poller to trigger, poller the message in BufferQueue submit to FixedThreadPool
poller_batch_size	100	the message size of every batch triggerd by the poller
redis_url	redis://127.0.0.1:6379/0	Redis backend url for Ratelimit and Unique Job
ratelimit_bucket_interval	1	Ratelimit use the time bucket (seconds) to store the counts, lower the more accurate
worker_buffer_flush_interval	6	Monkey patch, flush the Hutch::Worker.@buffer_queue message to RabbitMQ check interval

Hutch::Enqueue

Let consumer to include Hutch::Enqueue then it has the ability of publishing message to RabbitMQ with the consume '<routing_key>'.

Only support enqueue Hash format message

• enqueue: just publish one message
• enqueue_in: publish one message and delay seconds
• enqueue_at: publish one message and auto calculate the seconds need to delay
• enqueue_uniq(_in/at): publish uniq message with uniq_key

According to the RabbitMQ TTL Message design limits (discus), We design the fixed delay level from seconds to hours, below is the details:

• seconds(4): 5s, 10s, 20s, 30s
• minutes(14): 1m, 2m, 3m, 4m, 5m, 6m, 7m, 8m, 9m, 10m, 20m, 30m, 40m, 50m
• hours(3): 1h, 2h, 3h

RabbitMQ is not fit for storage lot`s of delay message so if you want delay an message beyand 3 hours so you need to storage it into database or some place.

Hutch::Threshold

Let consumer to include Hutch::Threshold to get the ability of threshold the message consume. It's automatic included when consumer include Hutch::Enqueue.

1. static configuration

class PlanConsumer
  include Hutch::Consumer
  include Hutch::Enqueue
  
  attempts 3
  consume 'abc.plan'
  # threshold 3 jobs per second
  threshold rate: 3, interval: 1
end

1. dynamic lambada

class PlanConsumer
  include Hutch::Consumer
  include Hutch::Enqueue
  
  attempts 3
  consume 'abc.plan'
  # threshold 2 jobs every 2 second with get_report context
  threshold -> { { context: 'get_report', rate: 2, interval: 2 } }
end

threshold lambada need get return value must be a Hash and include:

• context: the limit context with current threshold
• rate: the rate speed of threshold
• interval: the time range of threshold

Error Retry

If you want use error retry, then:

1. Add Hutch::ErrorHandlers::MaxRetry to Hutch::Config.error_handlers like below

Hutch::Config.error_handlers << Hutch::ErrorHandlers::MaxRetry.new

1. Let Hutch::Consumer to include Hutch::Enqueue and setup attempts

class PlanConsumer
  include Hutch::Consumer
  include Hutch::Enqueue
  
  attempts 3
  consume 'abc.plan'
end

Error retry will use ActiveJob exponentially_longer algorithm (executes**4) + 2 seconds

Rails

Work with Hutch it`s self

Add an hutch.rb to conf/initializers:

# reuse Hutch config.yaml file
Hutch::Config.load_from_file(Rails.root.join('config', 'config.yaml'))
# replace error_handlers with Hutch::ErrorHandlers::MaxRetry
Hutch::Config.error_handlers = [Hutch::ErrorHandlers::MaxRetry.new]
# Init Hutch and Hutch::Schedule
Hutch::Schedule.connect

Then you can enqueue message in Rails console like below:

PlanConsumer.enqueue(a: 1)
# or schedule message
PlanConsumer.enqueue_in(5.seconds, a: 1)

Work with ActiveJob

Config rails to use :hutch active_job adapter:

    config.active_job.queue_adapter     = :hutch
    config.active_job.queue_name_prefix = 'ajd'

class EmailJob < ApplicationJob
  queue_as :email
  
  retry_on StandardError, wait: :exponentially_longer
  
  def perform(user_id)
    user = User.find(user_id)
    user.send_email
  end
end

# in rails console, you can
EmailJob.perform_later(user.id)
# or
EmailJob.set(wait: 5.seconds).perform_later(user.id)

Limits

Because we use monkey patch to add some new features so if you direct use hutch cli and don't have some place to require hutch-schedule gem it won't be function.

• When direct use hutch cli only have one hook for rails app to load external depencency so if the app is not an rails app right now will not working.
• Hutch Config files must load during rails app initlization because monkey patch Hutch::Config need to load and then to work

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/wppurking/hutch-schedule. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

The gem is available as open source under the terms of the MIT License.

Performance

Use the repo: https://github.com/wppurking/hutch-schedule-demo

TODO

• add cron job support