module Octopus

Implementation courtesy of db-charmer.

The round-robin load balancing of slaves belonging to the same shard. It is a pool that contains slaves which queries are distributed to.

Implementation courtesy of db-charmer.

Adds current_shard as an attribute; provide a default implementation of set_current_shard which considers only the current ActiveRecord::Base.connection_proxy

Constants

VERSION

Attributes

logger[W]

Public Class Methods

config() click to toggle source

# File lib/octopus.rb, line 17
def self.config
  @config ||= begin
    file_name = File.join(Octopus.directory, 'config/shards.yml').to_s

    if File.exist?(file_name) || File.symlink?(file_name)
      config ||= HashWithIndifferentAccess.new(YAML.load(ERB.new(File.read(file_name)).result))[Octopus.env]
    else
      config ||= HashWithIndifferentAccess.new
    end

    config
  end
end

directory() click to toggle source

Returns the Rails.root_to_s when you are using rails Running the current directory in a generic Ruby process

# File lib/octopus.rb, line 60
def self.directory
  @directory ||= defined?(::Rails.root) ? Rails.root.to_s : Dir.pwd
end

enabled?() click to toggle source

Public: Whether or not Octopus is configured and should hook into the current environment. Checks the environments config option for the Rails environment by default.

Returns a boolean

# File lib/octopus.rb, line 48
def self.enabled?
  if defined?(::Rails.env)
    Octopus.environments.include?(Rails.env.to_s)
  else
    # TODO: This doens't feel right but !Octopus.config.blank? is breaking a
    #       test. Also, Octopus.config is always returning a hash.
    Octopus.config
  end
end

env() click to toggle source

# File lib/octopus.rb, line 9
def self.env
  @env ||= 'octopus'
end

environments() click to toggle source

# File lib/octopus.rb, line 75
def self.environments
  @environments ||= config['environments'] || ['production']
end

environments=(environments) click to toggle source

# File lib/octopus.rb, line 71
def self.environments=(environments)
  @environments = environments.map(&:to_s)
end

fully_replicated() { || ... } click to toggle source

# File lib/octopus.rb, line 150
def self.fully_replicated(&_block)
  old_fully_replicated = Thread.current[Octopus::Proxy::FULLY_REPLICATED_KEY]
  Thread.current[Octopus::Proxy::FULLY_REPLICATED_KEY] = true
  yield
ensure
  Thread.current[Octopus::Proxy::FULLY_REPLICATED_KEY] = old_fully_replicated
end

load_balancer() click to toggle source

# File lib/octopus.rb, line 35
def self.load_balancer
  @load_balancer ||= Octopus::LoadBalancing::RoundRobin
end

load_balancer=(balancer) click to toggle source

# File lib/octopus.rb, line 31
def self.load_balancer=(balancer)
  @load_balancer = balancer
end

logger() click to toggle source

# File lib/octopus.rb, line 107
def self.logger
  if defined?(Rails.logger)
    @logger ||= Rails.logger
  else
    @logger ||= Logger.new($stderr)
  end
end

master_shard() click to toggle source

# File lib/octopus.rb, line 39
def self.master_shard
  ((config && config[:master_shard]) || :master).to_sym
end

rails3?() click to toggle source

# File lib/octopus.rb, line 93
def self.rails3?
  ActiveRecord::VERSION::MAJOR <= 3
end

rails41?() click to toggle source

# File lib/octopus.rb, line 101
def self.rails41?
  rails4? && ActiveRecord::VERSION::MINOR >= 1
end

rails4?() click to toggle source

# File lib/octopus.rb, line 97
def self.rails4?
  ActiveRecord::VERSION::MAJOR >= 4
end

rails_env() click to toggle source

# File lib/octopus.rb, line 13
def self.rails_env
  @rails_env ||= defined?(::Rails.env) ? Rails.env.to_s : 'shards'
end

robust_environment?() click to toggle source

# File lib/octopus.rb, line 89
def self.robust_environment?
  robust_environments.include? rails_env
end

robust_environments() click to toggle source

Environments in which to swallow failures from a single shard when iterating through all.

# File lib/octopus.rb, line 85
def self.robust_environments
  @robust_environments ||= config['robust_environments'] || ['production']
end

robust_environments=(environments) click to toggle source

# File lib/octopus.rb, line 79
def self.robust_environments=(environments)
  @robust_environments = environments.map(&:to_s)
end

setup() { |self| ... } click to toggle source

This is the default way to do Octopus Setup Available variables: :enviroments => the enviroments that octopus will run. default: ‘production’

# File lib/octopus.rb, line 67
def self.setup
  yield self
end

shards=(shards) click to toggle source

# File lib/octopus.rb, line 115
def self.shards=(shards)
  config[rails_env] = HashWithIndifferentAccess.new(shards)
  ActiveRecord::Base.connection.initialize_shards(@config)
end

using(shard) { || ... } click to toggle source

# File lib/octopus.rb, line 120
def self.using(shard, &block)
  conn = ActiveRecord::Base.connection

  if conn.is_a?(Octopus::Proxy)
    conn.run_queries_on_shard(shard, &block)
  else
    yield
  end
end

using_all() { || ... } click to toggle source

# File lib/octopus.rb, line 140
def self.using_all(&block)
  conn = ActiveRecord::Base.connection

  if conn.is_a?(Octopus::Proxy)
    conn.send_queries_to_all_shards(&block)
  else
    yield
  end
end

using_group(group) { || ... } click to toggle source

# File lib/octopus.rb, line 130
def self.using_group(group, &block)
  conn = ActiveRecord::Base.connection

  if conn.is_a?(Octopus::Proxy)
    conn.send_queries_to_group(group, &block)
  else
    yield
  end
end