Class: Async::Service::Policy

Inherits:
Container::Policy
  • Object
show all
Defined in:
lib/async/service/policy.rb

Overview

A service-level policy that extends the base container policy with failure rate monitoring. This policy will stop the container if the failure rate exceeds a threshold.

Constant Summary collapse

DEFAULT =

The default service policy instance.

self.new.freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(maximum_failures: 6, window: 60) ⇒ Policy

Initialize the policy.



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# File 'lib/async/service/policy.rb', line 16

def initialize(maximum_failures: 6, window: 60)
  @maximum_failures = maximum_failures
  @window = window
  
  @failure_rate_threshold = maximum_failures.to_f / window
end

Instance Attribute Details

#failure_rate_threshold ⇒ Object

The failure rate threshold in failures per second.



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# File 'lib/async/service/policy.rb', line 33

def failure_rate_threshold
  @failure_rate_threshold
end

#maximum_failures ⇒ Object (readonly)

The maximum number of failures allowed within the window.



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# File 'lib/async/service/policy.rb', line 25

def maximum_failures
  @maximum_failures
end

#window ⇒ Object (readonly)

The time window in seconds for statistics tracking.



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# File 'lib/async/service/policy.rb', line 29

def window
  @window
end

Instance Method Details

#child_exit(container, child, status, name:, key:, **options) ⇒ Object

Called when a child exits. Monitors failure rate and stops the container if threshold is exceeded.



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# File 'lib/async/service/policy.rb', line 48

def child_exit(container, child, status, name:, key:, **options)
  unless success?(status)
    # Check failure rate after this failure is recorded
    rate = container.statistics.failure_rate.per_second
    
    if rate > @failure_rate_threshold
      # Only stop if container is not already stopping
      unless container.stopping?
        Console.error(self, "Failure rate exceeded threshold, stopping container!",
          rate: rate,
          threshold: @failure_rate_threshold
        )
        container.stop(true)
      end
    end
  end
end

#make_statistics ⇒ Object

Create statistics for a container with the configured window.



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# File 'lib/async/service/policy.rb', line 37

def make_statistics
  Async::Container::Statistics.new(window: @window)
end