Class: Switchman::DatabaseServer
- Inherits:
-
Object
- Object
- Switchman::DatabaseServer
- Defined in:
- lib/switchman/database_server.rb
Class Attribute Summary collapse
-
.creating_new_shard ⇒ Object
Returns the value of attribute creating_new_shard.
Instance Attribute Summary collapse
-
#id ⇒ Object
Returns the value of attribute id.
Class Method Summary collapse
- .all ⇒ Object
- .create(settings = {}) ⇒ Object
- .find(id_or_all) ⇒ Object
- .server_for_new_shard ⇒ Object
Instance Method Summary collapse
- #cache_store ⇒ Object
- #config(environment = :primary) ⇒ Object
- #create_new_shard(options = {}) ⇒ Object
- #destroy ⇒ Object
- #fake? ⇒ Boolean
-
#guard!(environment = :secondary) ⇒ Object
locks this db to a specific environment, except for when doing writes (then it falls back to the current value of GuardRail.environment).
- #guard_rail_environment ⇒ Object
-
#initialize(id = nil, config = {}) ⇒ DatabaseServer
constructor
A new instance of DatabaseServer.
- #pool_key ⇒ Object
- #primary_shard ⇒ Object
- #shard_name(shard) ⇒ Object
- #shards ⇒ Object
- #shareable? ⇒ Boolean
- #unguard ⇒ Object
- #unguard! ⇒ Object
Constructor Details
#initialize(id = nil, config = {}) ⇒ DatabaseServer
Returns a new instance of DatabaseServer.
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# File 'lib/switchman/database_server.rb', line 59 def initialize(id = nil, config = {}) @id = id @config = config.deep_symbolize_keys @configs = {} end |
Class Attribute Details
.creating_new_shard ⇒ Object
Returns the value of attribute creating_new_shard.
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# File 'lib/switchman/database_server.rb', line 10 def creating_new_shard @creating_new_shard end |
Instance Attribute Details
#id ⇒ Object
Returns the value of attribute id.
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# File 'lib/switchman/database_server.rb', line 7 def id @id end |
Class Method Details
.all ⇒ Object
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# File 'lib/switchman/database_server.rb', line 12 def all database_servers.values end |
.create(settings = {}) ⇒ Object
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# File 'lib/switchman/database_server.rb', line 22 def create(settings = {}) raise "database servers should be set up in database.yml" unless ::Rails.env.test? id = settings[:id] if !id @id ||= 0 @id += 1 id = @id end server = DatabaseServer.new(id.to_s, settings) server.instance_variable_set(:@fake, true) database_servers[server.id] = server end |
.find(id_or_all) ⇒ Object
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# File 'lib/switchman/database_server.rb', line 16 def find(id_or_all) return self.all if id_or_all == :all return id_or_all.map { |id| self.database_servers[id || ::Rails.env] }.compact.uniq if id_or_all.is_a?(Array) database_servers[id_or_all || ::Rails.env] end |
.server_for_new_shard ⇒ Object
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# File 'lib/switchman/database_server.rb', line 35 def server_for_new_shard servers = all.select { |s| s.config[:open] } return find(nil) if servers.empty? servers[rand(servers.length)] end |
Instance Method Details
#cache_store ⇒ Object
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# File 'lib/switchman/database_server.rb', line 260 def cache_store unless @cache_store @cache_store = Switchman.config[:cache_map][self.id] || Switchman.config[:cache_map][::Rails.env] end @cache_store end |
#config(environment = :primary) ⇒ Object
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# File 'lib/switchman/database_server.rb', line 74 def config(environment = :primary) @configs[environment] ||= begin if @config[environment].is_a?(Array) @config[environment].map do |config| config = @config.merge((config || {}).symbolize_keys) # make sure GuardRail doesn't get any brilliant ideas about choosing the first possible server config.delete(environment) config end elsif @config[environment].is_a?(Hash) @config.merge(@config[environment]) else @config end end end |
#create_new_shard(options = {}) ⇒ Object
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# File 'lib/switchman/database_server.rb', line 142 def create_new_shard( = {}) raise NotImplementedError.new("Cannot create new shards when sharding isn't initialized") unless Shard.default.is_a?(Shard) name = [:name] create_schema = [:schema] # look for another shard associated with this db other_shard = self.shards.where("name<>':memory:' OR name IS NULL").order(:id).first case config[:adapter] when 'postgresql' create_statement = lambda { "CREATE SCHEMA #{name}" } password = " PASSWORD #{::ActiveRecord::Base.connection.quote(config[:password])}" if config[:password] else create_statement = lambda { "CREATE DATABASE #{name}" } end sharding_config = Switchman.config config_create_statement = sharding_config[config[:adapter]]&.[](:create_statement) config_create_statement ||= sharding_config[:create_statement] if config_create_statement create_commands = Array(config_create_statement).dup create_statement = lambda { create_commands.map { |statement| statement.gsub('%{name}', name).gsub('%{password}', password || '') } } end create_shard = lambda do shard_id = .fetch(:id) do case config[:adapter] when 'postgresql' id_seq = Shard.connection.quote(Shard.connection.quote_table_name('switchman_shards_id_seq')) next_id = Shard.connection.select_value("SELECT nextval(#{id_seq})") next_id.to_i else nil end end if name.nil? base_name = self.config[:database].to_s % self.config base_name = nil if base_name == ':memory:' base_name << '_' if base_name base_id = shard_id || SecureRandom.uuid name = "#{base_name}shard_#{base_id}" end shard = Shard.create!(:id => shard_id, :name => name, :database_server => self) schema_already_existed = false begin self.class.creating_new_shard = true shard.activate(*Shard.categories) do ::GuardRail.activate(:deploy) do begin if create_statement if (::ActiveRecord::Base.connection.select_value("SELECT 1 FROM pg_namespace WHERE nspname=#{::ActiveRecord::Base.connection.quote(name)}")) schema_already_existed = true raise "This schema already exists; cannot overwrite" end Array(create_statement.call).each do |stmt| ::ActiveRecord::Base.connection.execute(stmt) end # have to disconnect and reconnect to the correct db if self.shareable? && other_shard other_shard.activate { ::ActiveRecord::Base.connection } else ::ActiveRecord::Base.connection_pool.current_pool.disconnect! end end old_proc = ::ActiveRecord::Base.connection.raw_connection.set_notice_processor {} if config[:adapter] == 'postgresql' old_verbose = ::ActiveRecord::Migration.verbose ::ActiveRecord::Migration.verbose = false unless create_schema == false reset_column_information migrate = ::Rails.version >= '5.2' ? -> { ::ActiveRecord::Base.connection.migration_context.migrate } : -> { ::ActiveRecord::Migrator.migrate(::ActiveRecord::Migrator.migrations_paths) } if ::ActiveRecord::Base.connection.supports_ddl_transactions? ::ActiveRecord::Base.connection.transaction(requires_new: true, &migrate) else migrate.call end reset_column_information ::ActiveRecord::Base.descendants.reject { |m| m == Shard || !m.table_exists? }.each(&:define_attribute_methods) end ensure ::ActiveRecord::Migration.verbose = old_verbose ::ActiveRecord::Base.connection.raw_connection.set_notice_processor(&old_proc) if old_proc end end end shard rescue shard.destroy unless schema_already_existed shard.drop_database rescue nil end reset_column_information unless create_schema == false rescue nil raise ensure self.class.creating_new_shard = false end end if Shard.connection.supports_ddl_transactions? && self.shareable? && other_shard Shard.transaction do other_shard.activate do ::ActiveRecord::Base.connection.transaction(&create_shard) end end else create_shard.call end end |
#destroy ⇒ Object
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# File 'lib/switchman/database_server.rb', line 65 def destroy raise "database servers should be set up in database.yml" unless ::Rails.env.test? self.class.send(:database_servers).delete(self.id) if self.id end |
#fake? ⇒ Boolean
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# File 'lib/switchman/database_server.rb', line 70 def fake? @fake end |
#guard!(environment = :secondary) ⇒ Object
locks this db to a specific environment, except for when doing writes (then it falls back to the current value of GuardRail.environment)
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# File 'lib/switchman/database_server.rb', line 98 def guard!(environment = :secondary) @guard_rail_environment = environment end |
#guard_rail_environment ⇒ Object
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# File 'lib/switchman/database_server.rb', line 91 def guard_rail_environment @guard_rail_environment || ::GuardRail.environment end |
#pool_key ⇒ Object
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# File 'lib/switchman/database_server.rb', line 138 def pool_key self.id == ::Rails.env ? nil : self.id end |
#primary_shard ⇒ Object
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# File 'lib/switchman/database_server.rb', line 283 def primary_shard unless instance_variable_defined?(:@primary_shard) # if sharding isn't fully set up yet, we may not be able to query the shards table @primary_shard = Shard.default if Shard.default.database_server == self @primary_shard ||= shards.where(name: nil).first end @primary_shard end |
#shard_name(shard) ⇒ Object
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# File 'lib/switchman/database_server.rb', line 267 def shard_name(shard) if config[:shard_name] config[:shard_name] elsif config[:adapter] == 'postgresql' if shard == :bootstrap # rescue nil because the database may not exist yet; if it doesn't, # it will shortly, and this will be re-invoked ::ActiveRecord::Base.connection.current_schemas.first rescue nil else shard.activate { ::ActiveRecord::Base.connection_pool.default_schema } end else config[:database] end end |
#shards ⇒ Object
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# File 'lib/switchman/database_server.rb', line 130 def shards if self.id == ::Rails.env Shard.where("database_server_id IS NULL OR database_server_id=?", self.id) else Shard.where(:database_server_id => self.id) end end |
#shareable? ⇒ Boolean
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# File 'lib/switchman/database_server.rb', line 114 def shareable? @shareable_environment_key ||= [] environment = guard_rail_environment explicit_user = ::GuardRail.global_config[:username] return @shareable if @shareable_environment_key == [environment, explicit_user] @shareable_environment_key = [environment, explicit_user] if explicit_user username = explicit_user else config = self.config(environment) config = config.first if config.is_a?(Array) username = config[:username] end @shareable = username !~ /%?\{[a-zA-Z0-9_]+\}/ end |
#unguard ⇒ Object
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# File 'lib/switchman/database_server.rb', line 106 def unguard old_env = @guard_rail_environment unguard! yield ensure guard!(old_env) end |
#unguard! ⇒ Object
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# File 'lib/switchman/database_server.rb', line 102 def unguard! @guard_rail_environment = nil end |