Class: Octopus::Proxy

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

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(config = Octopus.config) ⇒ Proxy

Returns a new instance of Proxy.



9
10
11
12
 
# File 'lib/octopus/proxy.rb', line 9

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 



260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
 
# File 'lib/octopus/proxy.rb', line 260

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.



7
8
9
 
# File 'lib/octopus/proxy.rb', line 7

def config
  @config
end

#sharded ⇒ Object

Returns the value of attribute sharded.



7
8
9
 
# File 'lib/octopus/proxy.rb', line 7

def sharded
  @sharded
end

Instance Method Details

#block ⇒ Object 



156
157
158
 
# File 'lib/octopus/proxy.rb', line 156

def block
  Thread.current['octopus.block']
end

#block=(block) ⇒ Object 



160
161
162
 
# File 'lib/octopus/proxy.rb', line 160

def block=(block)
  Thread.current['octopus.block'] = block
end

#check_schema_migrations(shard) ⇒ Object 



244
245
246
247
248
 
# File 'lib/octopus/proxy.rb', line 244

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 



237
238
239
240
241
242
 
# File 'lib/octopus/proxy.rb', line 237

def clean_connection_proxy
  self.current_shard = :master
  self.current_model = nil
  self.current_group = nil
  self.block = nil
end

#clear_active_connections! ⇒ Object 



298
299
300
 
# File 'lib/octopus/proxy.rb', line 298

def clear_active_connections!
  with_each_healthy_shard(&:release_connection)
end

#clear_all_connections! ⇒ Object 



302
303
304
 
# File 'lib/octopus/proxy.rb', line 302

def clear_all_connections!
  with_each_healthy_shard(&:disconnect!)
end

#clear_query_cache ⇒ Object 



294
295
296
 
# File 'lib/octopus/proxy.rb', line 294

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

#connected? ⇒ Boolean

Returns:

  • (Boolean) 


306
307
308
 
# File 'lib/octopus/proxy.rb', line 306

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

#connection_pool ⇒ Object 



281
282
283
 
# File 'lib/octopus/proxy.rb', line 281

def connection_pool
  @shards[current_shard]
end

#current_group ⇒ Object 



135
136
137
 
# File 'lib/octopus/proxy.rb', line 135

def current_group
  Thread.current['octopus.current_group']
end

#current_group=(group_symbol) ⇒ Object 



139
140
141
142
143
144
145
146
 
# File 'lib/octopus/proxy.rb', line 139

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['octopus.current_group'] = group_symbol
end

#current_model ⇒ Object 



92
93
94
 
# File 'lib/octopus/proxy.rb', line 92

def current_model
  Thread.current['octopus.current_model']
end

#current_model=(model) ⇒ Object 



96
97
98
 
# File 'lib/octopus/proxy.rb', line 96

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

#current_shard ⇒ Object 



100
101
102
 
# File 'lib/octopus/proxy.rb', line 100

def current_shard
  Thread.current['octopus.current_shard'] ||= :master
end

#current_shard=(shard_symbol) ⇒ Object 



104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
 
# File 'lib/octopus/proxy.rb', line 104

def current_shard=(shard_symbol)
  self.current_slave_group = nil
  if shard_symbol.is_a?(Array)
    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]

    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
      self.current_slave_group = slave_group_symbol
    end
  else
    fail "Nonexistent Shard Name: #{shard_symbol}" if @shards[shard_symbol].nil?
  end

  Thread.current['octopus.current_shard'] = shard_symbol
end

#current_slave_group ⇒ Object 



148
149
150
 
# File 'lib/octopus/proxy.rb', line 148

def current_slave_group
  Thread.current['octopus.current_slave_group']
end

#current_slave_group=(slave_group_symbol) ⇒ Object 



152
153
154
 
# File 'lib/octopus/proxy.rb', line 152

def current_slave_group=(slave_group_symbol)
  Thread.current['octopus.current_slave_group'] = slave_group_symbol
end

#disable_query_cache! ⇒ Object 



290
291
292
 
# File 'lib/octopus/proxy.rb', line 290

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

#enable_query_cache! ⇒ Object 



285
286
287
288
 
# File 'lib/octopus/proxy.rb', line 285

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) 


172
173
174
 
# File 'lib/octopus/proxy.rb', line 172

def fully_replicated?
  @fully_replicated || Thread.current['octopus.fully_replicated']
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) 


180
181
182
 
# File 'lib/octopus/proxy.rb', line 180

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

#initialize_replication(config) ⇒ Object 



79
80
81
82
83
84
85
86
87
88
89
90
 
# File 'lib/octopus/proxy.rb', line 79

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::LoadBalancing::RoundRobin.new(@slaves_list)
end

#initialize_shards(config) ⇒ Object 



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
 
# File 'lib/octopus/proxy.rb', line 14

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
end

#last_current_shard ⇒ Object 



164
165
166
 
# File 'lib/octopus/proxy.rb', line 164

def last_current_shard
  Thread.current['octopus.last_current_shard']
end

#last_current_shard=(last_current_shard) ⇒ Object 



168
169
170
 
# File 'lib/octopus/proxy.rb', line 168

def last_current_shard=(last_current_shard)
  Thread.current['octopus.last_current_shard'] = last_current_shard
end

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

Returns:

  • (Boolean) 


277
278
279
 
# File 'lib/octopus/proxy.rb', line 277

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

#run_queries_on_shard(shard, &_block) ⇒ Object 



223
224
225
226
227
228
229
 
# File 'lib/octopus/proxy.rb', line 223

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.



203
204
205
206
207
208
209
 
# File 'lib/octopus/proxy.rb', line 203

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

#select_connection ⇒ Object 



211
212
213
 
# File 'lib/octopus/proxy.rb', line 211

def select_connection
  safe_connection(@shards[shard_name])
end

#send_queries_to_multiple_shards(shards, &block) ⇒ Object 



231
232
233
234
235
 
# File 'lib/octopus/proxy.rb', line 231

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

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



314
315
316
 
# File 'lib/octopus/proxy.rb', line 314

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 



322
323
324
 
# File 'lib/octopus/proxy.rb', line 322

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 



215
216
217
 
# File 'lib/octopus/proxy.rb', line 215

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



187
188
189
 
# File 'lib/octopus/proxy.rb', line 187

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.



195
196
197
 
# File 'lib/octopus/proxy.rb', line 195

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

#should_clean_table_name? ⇒ Boolean

Returns:

  • (Boolean) 


219
220
221
 
# File 'lib/octopus/proxy.rb', line 219

def should_clean_table_name?
  @adapters.size > 1
end

#should_send_queries_to_shard_slave_group?(method) ⇒ Boolean

Returns:

  • (Boolean) 


310
311
312
 
# File 'lib/octopus/proxy.rb', line 310

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) 


318
319
320
 
# File 'lib/octopus/proxy.rb', line 318

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 



250
251
252
253
254
255
256
257
258
 
# File 'lib/octopus/proxy.rb', line 250

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