Module: OCI::Retry::Functions::Sleep

Defined in:
lib/oci/retry/functions/sleep.rb

Overview

A module containing functions that can be used to calculate sleep times between retries.

These functions should take two arguments: the first argument an object of type RetryConfig and the second an object of type Internal::RetryState

Class Method Summary collapse

Class Method Details

.exponential_backoff_with_equal_jitter ⇒ Proc

Returns a proc which applies an exponential backoff with equal jitter calclulation. This is defined as:

base_sleep_time = min(base_sleep_time * (exponent**attempts), max_sleep_time) (base_sleep_time / 2) + random(0, (base_sleep_time / 2))

Where the base_sleep_time, exponent, max_sleep_time_between_attempts is taken from the RetryConfig provided to the proc and the attempts is taken from the Internal::RetryState provided to the proc.

Returns:

  • (Proc) 


49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
 
# File 'lib/oci/retry/functions/sleep.rb', line 49

def self.exponential_backoff_with_equal_jitter
  lambda do |retry_config, retry_state|
    random = Random.new
    attempt = retry_state.current_attempt_number
    base_sleep_millis = retry_config.base_sleep_time_millis
    exponential_growth_factor = retry_config.exponential_growth_factor
    max_sleep_time_millis = retry_config.max_sleep_between_attempts_millis

    sleep_raw = if max_sleep_time_millis.nil?
                  base_sleep_millis * (exponential_growth_factor**attempt)
                else
                  [base_sleep_millis * (exponential_growth_factor**attempt), max_sleep_time_millis].min
                end
    (sleep_raw / 2) + random.rand(0..(sleep_raw / 2))
  end
end

.exponential_backoff_with_full_jitter ⇒ Proc

Returns a proc which applies an exponential backoff with full jitter calculation. This is defined as:

random(0, min(base_sleep_time * (exponent**attempts), max_sleep_time_between_attempts))

Where the base_sleep_time, exponent, max_sleep_time_between_attempts is taken from the RetryConfig provided to the proc and the attempts is taken from the Internal::RetryState provided to the proc.

Returns:

  • (Proc) 


22
23
24
25
26
27
28
29
30
31
32
33
34
35
 
# File 'lib/oci/retry/functions/sleep.rb', line 22

def self.exponential_backoff_with_full_jitter
  lambda do |retry_config, retry_state|
    random = Random.new
    attempt = retry_state.current_attempt_number
    base_sleep_millis = retry_config.base_sleep_time_millis
    exponential_growth_factor = retry_config.exponential_growth_factor
    max_sleep_time_millis = retry_config.max_sleep_between_attempts_millis

    return random.rand(0..(base_sleep_millis * (exponential_growth_factor**attempt))) \
      if max_sleep_time_millis.nil?

    random.rand(0..[base_sleep_millis * (exponential_growth_factor**attempt), max_sleep_time_millis].min)
  end
end

.exponential_backoff_with_full_jitter_equal_on_throttle ⇒ Proc

Returns a proc which uses exponential backoff with full jitter for retries, except in the case of throttles where exponential backoff with equal jitter is used instead. This ensures some base level of sleep for throttles rather than, potentially, retrying again in quick succession

Returns:

  • (Proc) 


72
73
74
75
76
77
78
79
80
81
82
83
 
# File 'lib/oci/retry/functions/sleep.rb', line 72

def self.exponential_backoff_with_full_jitter_equal_on_throttle
  lambda do |retry_config, retry_state|
    use_equal_jitter =
      !retry_state.last_exception.nil? &&
      retry_state.last_exception.respond_to?(:status_code) &&
      retry_state.last_exception.status_code == 429

    return exponential_backoff_with_full_jitter.call(retry_config, retry_state) unless use_equal_jitter

    exponential_backoff_with_equal_jitter.call(retry_config, retry_state)
  end
end