Class: HawatelTlb::Mode::Weighted

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

Constant Summary collapse

HISTORY_SIZE =

number of elements stored in history array

3

Instance Method Summary collapse

Constructor Details

#initialize(group) ⇒ Weighted

Returns a new instance of Weighted.



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# File 'lib/hawatel_tlb/mode/weighted.rb', line 7

def initialize(group)
  @group   = group
  @history = Array.new
  @counter = 0
end

Instance Method Details

#node ⇒ Hash

Returns hostname/ip address and port number.

Returns:

  • (Hash) —

    hostname/ip address and port number



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# File 'lib/hawatel_tlb/mode/weighted.rb', line 22

def node

  # push nodes statistics to history array
  if @counter < HISTORY_SIZE
    @history[@counter] = @group.dup
    @counter += 1
  else
    @counter = 0
    @history[@counter] = @group.dup
  end

  # build array with only
  current_online = Array.new
  @group.each do |node|
    current_online.push(node.id) if node.state == 'enable' && node.status[:state] == 'online'
  end

  # there is no any available node
  return false if current_online.empty?

  # there is only one available node
  return find_node(current_online[0]) if current_online.size == 1

  # there is more that one nodes - choose the most reliable node
  nodes_reliability = Array.new
  @history.each do |round|
    round.each do |node|
      if node.state == 'enable' && node.status[:state] == 'online'
        nodes_reliability[node.id] =  Hash.new if nodes_reliability[node.id].nil?
        nodes_reliability[node.id][:online_count] = 0 if nodes_reliability[node.id][:online_count].nil?
        nodes_reliability[node.id][:online_count] += 1
      end
    end
  end

  # choose only top nodes with equal online state
  top_nodes_by_state = Array.new
  top_value = 0
  sort_by_state(nodes_reliability).each do |node|
    top_value = node[:online_count] if top_value == 0
    if node[:online_count] == top_value
      node_param = @group.select {|item| item[:id] == node[:hostid]}
      top_nodes_by_state << node_param
    else
      break
    end
  end

  # there is only one node with highest online count
  return {:host => top_nodes_by_state[0][:host], port => top_nodes_by_state[0][:port]} if top_nodes_by_state.size == 1

  # find node with highest weight
  nodes = sort_by_weight(top_nodes_by_state)
  return {:host => nodes[0][0].host, :port => nodes[0][0].port}
end

#refresh(group) ⇒ Object

Refresh group table after delete or add host

Parameters:

  • group (Array<Hash>) 


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# File 'lib/hawatel_tlb/mode/weighted.rb', line 16

def refresh(group)
  @group = group
end