Class: Aspera::Transfer::Resumer

Inherits:
Object
  • Object
show all
Defined in:
lib/aspera/transfer/resumer.rb

Overview

Implements a simple resume policy

Instance Method Summary collapse

Constructor Details

#initialize(iter_max: 7, sleep_initial: 2, sleep_factor: 2, sleep_max: 60) ⇒ Resumer

Returns a new instance of Resumer.

Parameters:

  • iter_max (Integer) (defaults to: 7) —

    Maximum number of executions

  • sleep_initial (Integer) (defaults to: 2) —

    Initial wait to re-execute

  • sleep_factor (Integer) (defaults to: 2) —

    Multiplier

  • sleep_max. (Integer) —

    Max iterations



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# File 'lib/aspera/transfer/resumer.rb', line 16

def initialize(
  iter_max: 7,
  sleep_initial: 2,
  sleep_factor:  2,
  sleep_max:     60
)
  Aspera.assert_type(iter_max, Integer){k}
  @iter_max = iter_max
  Aspera.assert_type(sleep_initial, Integer){k}
  @sleep_initial = sleep_initial
  Aspera.assert_type(sleep_factor, Integer){k}
  @sleep_factor = sleep_factor
  Aspera.assert_type(sleep_max, Integer){k}
  @sleep_max = sleep_max
end

Instance Method Details

#execute_with_resume ⇒ Object

Calls block a number of times (resumes) until success or limit reached This is re-entrant, one resumer can handle multiple transfers in //

Parameters:

  • block (Proc) 


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# File 'lib/aspera/transfer/resumer.rb', line 36

def execute_with_resume
  Aspera.assert(block_given?)
  # maximum of retry
  remaining_resumes = @iter_max
  sleep_seconds = @sleep_initial
  Log.log.debug{"retries=#{remaining_resumes}"}
  # try to send the file until ascp is successful
  loop do
    Log.log.debug('Transfer session starting')
    begin
      # Call provided block: execute transfer
      yield
      # Exit retry loop if success
      break
    rescue Error => e
      Log.log.warn{"A transfer error occurred during transfer: #{e.message}"}
      Log.log.debug{"Retryable ? #{e.retryable?}"}
      # do not retry non-retryable
      raise unless e.retryable?
      # exit if we exceed the max number of retry
      raise Error, "Maximum number of retry reached: #{@iter_max}" if remaining_resumes <= 0
    end

    # take this retry in account
    remaining_resumes -= 1
    Log.log.warn{"Resuming in #{sleep_seconds} seconds (retry left:#{remaining_resumes})"}

    # wait a bit before retrying, maybe network condition will be better
    sleep(sleep_seconds)

    # increase retry period
    sleep_seconds *= @sleep_factor
    # cap value
    sleep_seconds = @sleep_max if sleep_seconds > @sleep_max
  end
end