Class: Octopus::Proxy

Inherits:
Object
  • Object
show all
Defined in:
lib/octopus/proxy.rb

Constant Summary collapse

CURRENT_MODEL_KEY = 
'octopus.current_model'.freeze
CURRENT_SHARD_KEY = 
'octopus.current_shard'.freeze
CURRENT_GROUP_KEY = 
'octopus.current_group'.freeze
CURRENT_SLAVE_GROUP_KEY = 
'octopus.current_slave_group'.freeze
CURRENT_LOAD_BALANCE_OPTIONS_KEY = 
'octopus.current_load_balance_options'.freeze
BLOCK_KEY = 
'octopus.block'.freeze
LAST_CURRENT_SHARD_KEY = 
'octopus.last_current_shard'.freeze
FULLY_REPLICATED_KEY = 
'octopus.fully_replicated'.freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(config = Octopus.config) ⇒ Proxy

Returns a new instance of Proxy.



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# File 'lib/octopus/proxy.rb', line 18

def initialize(config = Octopus.config)
  initialize_shards(config)
  initialize_replication(config) if !config.nil? && config['replicated']
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(method, *args, &block) ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 290

def method_missing(method, *args, &block)
  if should_clean_connection_proxy?(method)
    conn = select_connection
    self.last_current_shard = current_shard
    clean_connection_proxy
    conn.send(method, *args, &block)
  elsif should_send_queries_to_shard_slave_group?(method)
    send_queries_to_shard_slave_group(method, *args, &block)
  elsif should_send_queries_to_slave_group?(method)
    send_queries_to_slave_group(method, *args, &block)
  elsif should_send_queries_to_replicated_databases?(method)
    send_queries_to_selected_slave(method, *args, &block)
  else
    select_connection.send(method, *args, &block)
  end
end

Instance Attribute Details

#config ⇒ Object

Returns the value of attribute config.



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# File 'lib/octopus/proxy.rb', line 7

def config
  @config
end

#sharded ⇒ Object

Returns the value of attribute sharded.



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# File 'lib/octopus/proxy.rb', line 7

def sharded
  @sharded
end

Instance Method Details

#block ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 176

def block
  Thread.current[BLOCK_KEY]
end

#block=(block) ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 180

def block=(block)
  Thread.current[BLOCK_KEY] = block
end

#check_schema_migrations(shard) ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 274

def check_schema_migrations(shard)
  OctopusModel.using(shard).connection.table_exists?(
    ActiveRecord::Migrator.schema_migrations_table_name,
  ) || OctopusModel.using(shard).connection.initialize_schema_migrations_table
end

#clean_connection_proxy ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 267

def clean_connection_proxy
  self.current_shard = Octopus.master_shard
  self.current_model = nil
  self.current_group = nil
  self.block = nil
end

#clear_active_connections! ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 328

def clear_active_connections!
  with_each_healthy_shard(&:release_connection)
end

#clear_all_connections! ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 332

def clear_all_connections!
  with_each_healthy_shard(&:disconnect!)
end

#clear_query_cache ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 324

def clear_query_cache
  with_each_healthy_shard { |v| v.connected? && safe_connection(v).clear_query_cache }
end

#connected? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/octopus/proxy.rb', line 336

def connected?
  @shards.any? { |_k, v| v.connected? }
end

#connection_pool ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 311

def connection_pool
  @shards[current_shard]
end

#current_group ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 146

def current_group
  Thread.current[CURRENT_GROUP_KEY]
end

#current_group=(group_symbol) ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 150

def current_group=(group_symbol)
  # TODO: Error message should include all groups if given more than one bad name.
  [group_symbol].flatten.compact.each do |group|
    fail "Nonexistent Group Name: #{group}" unless has_group?(group)
  end

  Thread.current[CURRENT_GROUP_KEY] = group_symbol
end

#current_load_balance_options ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 168

def current_load_balance_options
  Thread.current[CURRENT_LOAD_BALANCE_OPTIONS_KEY]
end

#current_load_balance_options=(options) ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 172

def current_load_balance_options=(options)
  Thread.current[CURRENT_LOAD_BALANCE_OPTIONS_KEY] = options
end

#current_model ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 101

def current_model
  Thread.current[CURRENT_MODEL_KEY]
end

#current_model=(model) ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 105

def current_model=(model)
  Thread.current[CURRENT_MODEL_KEY] = model.is_a?(ActiveRecord::Base) ? model.class : model
end

#current_shard ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 109

def current_shard
  Thread.current[CURRENT_SHARD_KEY] ||= Octopus.master_shard
end

#current_shard=(shard_symbol) ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 113

def current_shard=(shard_symbol)
  if shard_symbol.is_a?(Array)
    self.current_slave_group = nil
    shard_symbol.each { |symbol| fail "Nonexistent Shard Name: #{symbol}" if @shards[symbol].nil? }
  elsif shard_symbol.is_a?(Hash)
    hash = shard_symbol
    shard_symbol = hash[:shard]
    slave_group_symbol = hash[:slave_group]
    load_balance_options = hash[:load_balance_options]

    if shard_symbol.nil? && slave_group_symbol.nil?
      fail 'Neither shard or slave group must be specified'
    end

    if shard_symbol.present?
      fail "Nonexistent Shard Name: #{shard_symbol}" if @shards[shard_symbol].nil?
    end

    if slave_group_symbol.present?
      if (@shards_slave_groups.try(:[], shard_symbol).present? && @shards_slave_groups[shard_symbol][slave_group_symbol].nil?) ||
          (@shards_slave_groups.try(:[], shard_symbol).nil? && @slave_groups[slave_group_symbol].nil?)
        fail "Nonexistent Slave Group Name: #{slave_group_symbol} in shards config: #{@shards_config.inspect}"
      end
    end
    self.current_slave_group = slave_group_symbol
    self.current_load_balance_options = load_balance_options
  else
    fail "Nonexistent Shard Name: #{shard_symbol}" if @shards[shard_symbol].nil?
  end

  Thread.current[CURRENT_SHARD_KEY] = shard_symbol
end

#current_slave_group ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 159

def current_slave_group
  Thread.current[CURRENT_SLAVE_GROUP_KEY]
end

#current_slave_group=(slave_group_symbol) ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 163

def current_slave_group=(slave_group_symbol)
  Thread.current[CURRENT_SLAVE_GROUP_KEY] = slave_group_symbol
  Thread.current[CURRENT_LOAD_BALANCE_OPTIONS_KEY] = nil if slave_group_symbol.nil?
end

#disable_query_cache! ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 320

def disable_query_cache!
  with_each_healthy_shard { |v| v.connected? && safe_connection(v).disable_query_cache! }
end

#enable_query_cache! ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 315

def enable_query_cache!
  clear_query_cache
  with_each_healthy_shard { |v| v.connected? && safe_connection(v).enable_query_cache! }
end

#fully_replicated? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/octopus/proxy.rb', line 192

def fully_replicated?
  @fully_replicated || Thread.current[FULLY_REPLICATED_KEY]
end

#has_group?(group) ⇒ Boolean

Public: Whether or not a group exists with the given name converted to a string.

Returns a boolean.

Returns:

  • (Boolean) 


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# File 'lib/octopus/proxy.rb', line 200

def has_group?(group)
  @groups.key?(group.to_s)
end

#initialize_replication(config) ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 88

def initialize_replication(config)
  @replicated = true
  if config.key?('fully_replicated')
    @fully_replicated = config['fully_replicated']
  else
    @fully_replicated = true
  end

  @slaves_list = @shards.keys.map(&:to_s).sort
  @slaves_list.delete('master')
  @slaves_load_balancer = Octopus.load_balancer.new(@slaves_list)
end

#initialize_shards(config) ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 23

def initialize_shards(config)
  @shards = HashWithIndifferentAccess.new
  @shards_slave_groups = HashWithIndifferentAccess.new
  @slave_groups = HashWithIndifferentAccess.new
  @groups = {}
  @adapters = Set.new
  @config = ActiveRecord::Base.connection_pool_without_octopus.spec.config

  unless config.nil?
    @entire_sharded = config['entire_sharded']
    @shards_config = config[Octopus.rails_env]
  end

  @shards_config ||= []

  @shards_config.each do |key, value|
    if value.is_a?(String)
      value = resolve_string_connection(value).merge(:octopus_shard => key)
      initialize_adapter(value['adapter'])
      @shards[key.to_sym] = connection_pool_for(value, "#{value['adapter']}_connection")
    elsif value.is_a?(Hash) && value.key?('adapter')
      value.merge!(:octopus_shard => key)
      initialize_adapter(value['adapter'])
      @shards[key.to_sym] = connection_pool_for(value, "#{value['adapter']}_connection")

      slave_group_configs = value.select do |_k, v|
        structurally_slave_group? v
      end

      if slave_group_configs.present?
        slave_groups = HashWithIndifferentAccess.new
        slave_group_configs.each do |slave_group_name, slave_configs|
          slaves = HashWithIndifferentAccess.new
          slave_configs.each do |slave_name, slave_config|
            @shards[slave_name.to_sym] = connection_pool_for(slave_config, "#{value['adapter']}_connection")
            slaves[slave_name.to_sym] = slave_name.to_sym
          end
          slave_groups[slave_group_name.to_sym] = Octopus::SlaveGroup.new(slaves)
        end
        @shards_slave_groups[key.to_sym] = slave_groups
        @sharded = true
      end
    elsif value.is_a?(Hash)
      @groups[key.to_s] = []

      value.each do |k, v|
        fail 'You have duplicated shard names!' if @shards.key?(k.to_sym)

        initialize_adapter(v['adapter'])
        config_with_octopus_shard = v.merge(:octopus_shard => k)

        @shards[k.to_sym] = connection_pool_for(config_with_octopus_shard, "#{v['adapter']}_connection")
        @groups[key.to_s] << k.to_sym
      end

      if structurally_slave_group? value
        slaves = Hash[@groups[key.to_s].map { |v| [v, v] }]
        @slave_groups[key.to_sym] = Octopus::SlaveGroup.new(slaves)
      end
    end
  end

  @shards[:master] ||= ActiveRecord::Base.connection_pool_without_octopus if Octopus.master_shard == :master
end

#last_current_shard ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 184

def last_current_shard
  Thread.current[LAST_CURRENT_SHARD_KEY]
end

#last_current_shard=(last_current_shard) ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 188

def last_current_shard=(last_current_shard)
  Thread.current[LAST_CURRENT_SHARD_KEY] = last_current_shard
end

#respond_to?(method, include_private = false) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/octopus/proxy.rb', line 307

def respond_to?(method, include_private = false)
  super || select_connection.respond_to?(method, include_private)
end

#run_queries_on_shard(shard, &_block) ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 243

def run_queries_on_shard(shard, &_block)
  keeping_connection_proxy(shard) do
    using_shard(shard) do
      yield
    end
  end
end

#safe_connection(connection_pool) ⇒ Object

Rails 3.1 sets automatic_reconnect to false when it removes connection pool. Octopus can potentially retain a reference to a closed connection pool. Previously, that would work since the pool would just reconnect, but in Rails 3.1 the flag prevents this.



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# File 'lib/octopus/proxy.rb', line 223

def safe_connection(connection_pool)
  connection_pool.automatic_reconnect ||= true
  if !connection_pool.connected? && @shards[Octopus.master_shard].connection.query_cache_enabled
    connection_pool.connection.enable_query_cache!
  end
  connection_pool.connection
end

#select_connection ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 231

def select_connection
  safe_connection(@shards[shard_name])
end

#send_queries_to_all_shards(&block) ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 263

def send_queries_to_all_shards(&block)
  send_queries_to_multiple_shards(shard_names.uniq { |shard_name| @shards[shard_name] }, &block)
end

#send_queries_to_group(group, &block) ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 257

def send_queries_to_group(group, &block)
  using_group(group) do
    send_queries_to_multiple_shards(shards_for_group(group), &block)
  end
end

#send_queries_to_multiple_shards(shards, &block) ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 251

def send_queries_to_multiple_shards(shards, &block)
  shards.map do |shard|
    run_queries_on_shard(shard, &block)
  end
end

#send_queries_to_shard_slave_group(method, *args, &block) ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 344

def send_queries_to_shard_slave_group(method, *args, &block)
  send_queries_to_balancer(@shards_slave_groups[current_shard][current_slave_group], method, *args, &block)
end

#send_queries_to_slave_group(method, *args, &block) ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 352

def send_queries_to_slave_group(method, *args, &block)
  send_queries_to_balancer(@slave_groups[current_slave_group], method, *args, &block)
end

#shard_name ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 235

def shard_name
  current_shard.is_a?(Array) ? current_shard.first : current_shard
end

#shard_names ⇒ Object

Public: Retrieves names of all loaded shards.

Returns an array of shard names as symbols



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# File 'lib/octopus/proxy.rb', line 207

def shard_names
  @shards.keys
end

#shards_for_group(group) ⇒ Object

Public: Retrieves the defined shards for a given group.

Returns an array of shard names as symbols or nil if the group is not defined.



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# File 'lib/octopus/proxy.rb', line 215

def shards_for_group(group)
  @groups.fetch(group.to_s, nil)
end

#should_clean_table_name? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/octopus/proxy.rb', line 239

def should_clean_table_name?
  @adapters.size > 1
end

#should_send_queries_to_shard_slave_group?(method) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/octopus/proxy.rb', line 340

def should_send_queries_to_shard_slave_group?(method)
  should_use_slaves_for_method?(method) && @shards_slave_groups.try(:[], current_shard).try(:[], current_slave_group).present?
end

#should_send_queries_to_slave_group?(method) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/octopus/proxy.rb', line 348

def should_send_queries_to_slave_group?(method)
  should_use_slaves_for_method?(method) && @slave_groups.try(:[], current_slave_group).present?
end

#transaction(options = {}, &block) ⇒ Object 



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# File 'lib/octopus/proxy.rb', line 280

def transaction(options = {}, &block)
  if !sharded && current_model_replicated?
    run_queries_on_shard(Octopus.master_shard) do
      select_connection.transaction(options, &block)
    end
  else
    select_connection.transaction(options, &block)
  end
end