https://github.com/remind101/all_my_circuits

Mostly threadsafe implementation of the CircuitBreaker pattern for Ruby.
https://github.com/remind101/all_my_circuits

Last synced: 5 months ago
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Mostly threadsafe implementation of the CircuitBreaker pattern for Ruby.

• Host: GitHub
• URL: https://github.com/remind101/all_my_circuits
• Owner: remind101
• License: bsd-2-clause
• Created: 2015-05-23T01:45:44.000Z (about 11 years ago)
• Default Branch: master
• Last Pushed: 2017-04-12T18:28:01.000Z (over 9 years ago)
• Last Synced: 2025-12-28T16:57:55.136Z (7 months ago)
• Language: Ruby
• Homepage:
• Size: 92.8 KB
• Stars: 1
• Watchers: 80
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

          
# AllMyCircuits

[![Circle CI](https://circleci.com/gh/remind101/all_my_circuits.svg?style=svg&circle-token=3c0f7294a61e095f789f369f96bdd266ddd80258)](https://circleci.com/gh/remind101/all_my_circuits)

![funny image goes here](https://raw.githubusercontent.com/remind101/all_my_circuits/master/all_my_circuits.jpg?token=AAc0YcX8xOhT0o4_Ko-IxKEEQk2PTUJYks5VaR0ywA%3D%3D)

AllMyCircuits is intended to be a threadsafe-ish circuit breaker implementation for Ruby.

See [Martin Fowler's article on the Circuit Breaker pattern for more info](http://martinfowler.com/bliki/CircuitBreaker.html).

# Usage

    class MyService

      include Singleton

      def initialize

        @circuit_breaker = AllMyCircuits::Breaker.new(

          name: "my_service",

          watch_errors: [Timeout::Error],               # defaults to AllMyCircuits::Breaker.net_errors,

                                                        #   which includes typical net/http and socket errors

          sleep_seconds: 10,                            # leave circuit open for 10 seconds, than try to call the service again

          strategy: AllMyCircuits::Strategies::PercentageOverWindowStrategy.new(

            requests_window: 100,                       # number of requests to calculate the average failure rate for

            failure_rate_percent_threshold: 25          # open circuit if 25% or more requests within 100-request window fail

                                                        #   must trip open again if the first request fails

          }

        )

      end

      def run

        begin

          @breaker.run do

            Timeout.timeout(1.0) { my_risky_call }

          end

        rescue AllMyCircuits::BreakerOpen => e

          # log me somewhere

        rescue

          # uh-oh, risky call failed once

        end

      end

    end

# Testing

So, what have we got:

  * Time-sensitive code: ...check

  * Concurrent code:     ...check

Dude, that's a real headache for someone who's not confortable enough with concurrent code.

I haven't figured any awesome way of automated testing in this case.

So, in the [script](https://github.com/remind101/all_my_circuits/tree/master/script) folder, there are:

  * [fake_service.rb](https://github.com/remind101/all_my_circuits/blob/master/script/fake_service.rb)

  * [graphing_stress_test.rb](https://github.com/remind101/all_my_circuits/blob/master/script/graphing_stress_test.rb)

## fake_service.rb

the Fake Service has 3 modes of operation: `up` (default), `die` and `slowdown`.

  * `up` (default) - http://localhost:8081/up - normal mode of operation, latency up to 50ms

  * `die` - http://localhost:8081/die - exceptions are raised left and right, slight delay in response

  * `slowdown` - http://localhost:8081/slowdown - successful responses with a significant delay.

## Graphing Stress Test

runs `WORKERS` number of workers which continuously hit http://localhost:8081. Graphs are served at http://localhost:8080.

This app allows to catch incorrect circuit breaker behavior visually.

# Logging

Logger can be configured by setting `AllMyCircuits.logger`.

Default log device is STDERR, and default level is ERROR (can be overridden with `ALL_MY_CIRCUITS_LOG_LEVEL` environment variable).

# TODO

  * global controls through redis?