Class: Resilient::CircuitBreaker::Properties

Inherits:
Object
  • Object
show all
Defined in:
lib/resilient/circuit_breaker/properties.rb

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options = {}) ⇒ Properties

Returns a new instance of Properties.



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# File 'lib/resilient/circuit_breaker/properties.rb', line 53

def initialize(options = {})
  @force_open = options.fetch(:force_open, false)
  @force_closed = options.fetch(:force_closed, false)
  @instrumenter = options.fetch(:instrumenter, Instrumenters::Noop)
  @sleep_window_seconds = options.fetch(:sleep_window_seconds, 5)
  @request_volume_threshold = options.fetch(:request_volume_threshold, 20)
  @error_threshold_percentage = options.fetch(:error_threshold_percentage, 50)
  @window_size_in_seconds = options.fetch(:window_size_in_seconds, 60)
  @bucket_size_in_seconds = options.fetch(:bucket_size_in_seconds, 10)

  if @bucket_size_in_seconds >= @window_size_in_seconds
    raise ArgumentError, "bucket_size_in_seconds must be smaller than window_size_in_seconds"
  end

  if @window_size_in_seconds % @bucket_size_in_seconds != 0
    raise ArgumentError,
      "window_size_in_seconds must be perfectly divisible by" +
      " bucket_size_in_seconds in order to evenly partition the buckets"
  end

  @metrics = options.fetch(:metrics) {
    Metrics.new({
      window_size_in_seconds: @window_size_in_seconds,
      bucket_size_in_seconds: @bucket_size_in_seconds,
    })
  }
end

Instance Attribute Details

#bucket_size_in_seconds ⇒ Object (readonly)

size of buckets in statistical window



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# File 'lib/resilient/circuit_breaker/properties.rb', line 48

def bucket_size_in_seconds
  @bucket_size_in_seconds
end

#error_threshold_percentage ⇒ Object (readonly)

% of “marks” that must be failed to trip the circuit



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# File 'lib/resilient/circuit_breaker/properties.rb', line 42

def error_threshold_percentage
  @error_threshold_percentage
end

#force_closed ⇒ Object (readonly)

allows ignoring errors and therefore never trip “open” (ie. allow all traffic through); normal instrumentation will still happen, thus allowing you to “test” configuration live without impact



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# File 'lib/resilient/circuit_breaker/properties.rb', line 28

def force_closed
  @force_closed
end

#force_open ⇒ Object (readonly)

allows forcing the circuit open (stopping all requests)



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# File 'lib/resilient/circuit_breaker/properties.rb', line 23

def force_open
  @force_open
end

#instrumenter ⇒ Object (readonly)

what to use to instrument all events that happen (ie: ActiveSupport::Notifications)



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# File 'lib/resilient/circuit_breaker/properties.rb', line 32

def instrumenter
  @instrumenter
end

#metrics ⇒ Object (readonly)

metrics instance used to keep track of success and failure



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# File 'lib/resilient/circuit_breaker/properties.rb', line 51

def metrics
  @metrics
end

#request_volume_threshold ⇒ Object (readonly)

number of requests that must be made within a statistical window before open/close decisions are made using stats



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# File 'lib/resilient/circuit_breaker/properties.rb', line 39

def request_volume_threshold
  @request_volume_threshold
end

#sleep_window_seconds ⇒ Object (readonly)

seconds after tripping circuit before allowing retry



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# File 'lib/resilient/circuit_breaker/properties.rb', line 35

def sleep_window_seconds
  @sleep_window_seconds
end

#window_size_in_seconds ⇒ Object (readonly)

number of seconds in the statistical window



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# File 'lib/resilient/circuit_breaker/properties.rb', line 45

def window_size_in_seconds
  @window_size_in_seconds
end

Class Method Details

.wrap(hash_or_instance) ⇒ Object

Internal: Takes a string name or instance of a Key and always returns a Key instance.



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# File 'lib/resilient/circuit_breaker/properties.rb', line 9

def self.wrap(hash_or_instance)
  case hash_or_instance
  when self
    hash_or_instance
  when Hash
    new(hash_or_instance)
  when NilClass
    new
  else
    raise TypeError, "properties must be Hash or Resilient::Properties instance"
  end
end