Class: SolidCache::Entry::Size::MovingAverageEstimate

Inherits:
Object
  • Object
show all
Defined in:
app/models/solid_cache/entry/size/moving_average_estimate.rb

Overview

Moving average cache size estimation

To reduce variability in the cache size estimate, we’ll use a moving average of the previous 20 estimates. The estimates are stored directly in the cache, under the “__solid_cache_entry_size_moving_average_estimates” key.

We’ll remove the largest and smallest estimates, and then average remaining ones.

Constant Summary collapse

ESTIMATES_KEY = 
"__solid_cache_entry_size_moving_average_estimates"
MAX_RETAINED_ESTIMATES = 
50
TARGET_SAMPLED_FRACTION = 
0.0005

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(samples:) ⇒ MovingAverageEstimate

Returns a new instance of MovingAverageEstimate.



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# File 'app/models/solid_cache/entry/size/moving_average_estimate.rb', line 20

def initialize(samples:)
  @samples = samples
  @estimate = Estimate.new(samples: samples)
  values = latest_values
  @size = (values.sum / values.size.to_f).round
  write_values(values)
end

Instance Attribute Details

#samples ⇒ Object (readonly)

Returns the value of attribute samples.



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# File 'app/models/solid_cache/entry/size/moving_average_estimate.rb', line 17

def samples
  @samples
end

#size ⇒ Object (readonly)

Returns the value of attribute size.



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# File 'app/models/solid_cache/entry/size/moving_average_estimate.rb', line 17

def size
  @size
end