Resque::Latency

This is a Resque plugin for storing the number of seconds that your queues are backed up.

Monitoring and alerting based on queue size is not a reliable metric. In a large enough queue system, it can be common for a queue to contain thousands of jobs, but abnormal for it to take too much time for a job to be performed after being enqueued.

Store a constant tally of the number of seconds that each queue takes to process a job after enqueuing. Also, stores the datestamp for when the metric was last updated.

Installation

This gem is a work in progress and has not been pushed to rubygems. In the meantime, point your gemfile or installation script to this github repository.

Add this line to your application's Gemfile:

gem 'resque-latency'

And then execute:

$ bundle

Or install it yourself as:

$ gem install resque-latency

Usage

This gem automatically adds a 'timestamp' to the payload of every job. When the job gets picked up by a Resque worker, the timestamp is read and compared to the curren timestamp, then a key (resque:latency:QUEUE_NAME) is updated to reflect the number of seconds and also includes the current datestamp, so you know when this value was last updated.

Two new methods are added to the Resque object:

• Resque.latency(queue)
• Resque.latency_updated_at(queue)

Resque.latency

Given a queue name, this is the number of seconds that the last job performed from this queue took to be started after being enqueued.

Resque.latency_updated_at

Given a queue name, this will return a Time object of when the last job was performed from this queue. This value is there so you know if the latency metric is out of date.

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request