Class: HawatelTlb::Mode::Ratio

Inherits:
Object
  • Object
show all
Defined in:
lib/hawatel_tlb/mode/ratio.rb

Overview

Ratio algorithm

Thease are static load balancing algorithm based on ratio weights. Algorithm explanation:

  1. divide the amount of traffic (requests) sent to each server by weight (configured in the Client)

  2. Sort by ratio (result from 1. point) from smallest to largest

  3. Get node with smallest ratio

If you want to see how it works you can set client.mode.debug to 1 and run ratio_spec.rb.

Direct Known Subclasses

DynamicRatio

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(group) ⇒ Ratio

Returns a new instance of Ratio.



15
16
17
18
19
20
21
22
23
24
25
26
27
28
 
# File 'lib/hawatel_tlb/mode/ratio.rb', line 15

def initialize(group)
  @traffic = 0
  @debug = 0

  group.each do |node|
    node.ratio = Hash.new
    node.ratio[:traffic] = 0
    node.ratio[:value] = 0

    node.weight = 1 if node.weight.to_i < 1
  end

  @group = group
end

Instance Attribute Details

#debug ⇒ Object

Ratio algorithm

Thease are static load balancing algorithm based on ratio weights. Algorithm explanation:

  1. divide the amount of traffic (requests) sent to each server by weight (configured in the Client)

  2. Sort by ratio (result from 1. point) from smallest to largest

  3. Get node with smallest ratio

If you want to see how it works you can set client.mode.debug to 1 and run ratio_spec.rb.



12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
 
# File 'lib/hawatel_tlb/mode/ratio.rb', line 12

class Ratio
  attr_accessor :debug

  def initialize(group)
    @traffic = 0
    @debug = 0

    group.each do |node|
      node.ratio = Hash.new
      node.ratio[:traffic] = 0
      node.ratio[:value] = 0

      node.weight = 1 if node.weight.to_i < 1
    end

    @group = group
  end

  # Refresh group table after delete or add host
  #
  # @param group [Array<Hash>]
  def refresh(group)
    @group = group
  end

  # Description
  # @param name [Type] description
  # @option name [Type] :opt description
  # @example
  #   mode = Ratio.new(nodes)
  #   p mode.node
  # @return [Hash] :host and :port
  def node
    node = get_right_node
    return {:host => node.host, :port => node.port} if node
    false
  end

  private

  def get_right_node
    nodes = sort_nodes_by_ratio_asc
    node = get_first_online_node(nodes)
    debug_log(nodes)

    if node
      set_ratio(node)
      return node
    else
      false
    end
  end

  def get_first_online_node(nodes)
    nodes.each do |node|
      return node if node.status[:state] == 'online' && node.state == 'enable'
    end
    false
  end

  def sort_nodes_by_ratio_asc
    @group.sort_by {|node| node.ratio[:value]}
  end

  def set_ratio(node)
    @traffic += 1
    node.ratio[:traffic] += 1
    node.ratio[:value] = calc_ratio(node.ratio[:traffic], node.weight)
  end

  def calc_ratio(traffic, weight)
    if weight.zero?
      0
    else
      traffic.to_f / weight.to_f
    end
  end

  def debug_log(nodes)
    if @debug > 0
      puts ">> request: #{@traffic} | selected #{nodes[0].host}"
      nodes.each do |node|
        puts "\t" "#{node.host} - ratio: #{node.ratio}, weight: #{node.weight}\n"
      end
      puts "------------------------------------------------------------"
    end
  end

end

Instance Method Details

#node ⇒ Hash

Description

Examples:

mode = Ratio.new(nodes)
p mode.node

Parameters:

  • name (Type) —

    description

Returns:

  • (Hash) —

    :host and :port



44
45
46
47
48
 
# File 'lib/hawatel_tlb/mode/ratio.rb', line 44

def node
  node = get_right_node
  return {:host => node.host, :port => node.port} if node
  false
end

#refresh(group) ⇒ Object

Refresh group table after delete or add host

Parameters:

  • group (Array<Hash>) 


33
34
35
 
# File 'lib/hawatel_tlb/mode/ratio.rb', line 33

def refresh(group)
  @group = group
end