MHAのフェイルオーバー時に再接続するための修正

abstract_mysql_adapter.rb.diff

--- /usr/lib/ruby/gems/1.8/gems/activerecord-3.2.15/lib/active_record/connection_adapters/abstract_mysql_adapter.rb.orig	2013-10-31 07:37:55.704402703 +0000
+++ /usr/lib/ruby/gems/1.8/gems/activerecord-3.2.15/lib/active_record/connection_adapters/abstract_mysql_adapter.rb.reconnect	2013-10-31 09:18:52.061099228 +0000
@@ -239,11 +239,16 @@

       # Executes the SQL statement in the context of this connection.
       def execute(sql, name = nil)
+        begin
         if name == :skip_logging
           @connection.query(sql)
         else
           log(sql, name) { @connection.query(sql) }
         end
+        rescue Mysql2::Error
+          sleep 0.3
+          retry
+        end
       rescue ActiveRecord::StatementInvalid => exception
         if exception.message.split(":").first =~ /Packets out of order/
           raise ActiveRecord::StatementInvalid, "'Packets out of order' error was received from the database. Please update your mysql bindings (gem install mysql) and read http://dev.mysql.com/doc/mysql/en/password-hashing.html for more information. If you're on Windows, use the Instant Rails installer to get the updated mysql bindings."

mysql2_adapter.rb.diff

--- /usr/lib/ruby/gems/1.8/gems/activerecord-3.2.15/lib/active_record/connection_adapters/mysql2_adapter.rb.orig	2013-10-31 09:27:51.300829040 +0000
+++ /usr/lib/ruby/gems/1.8/gems/activerecord-3.2.15/lib/active_record/connection_adapters/mysql2_adapter.rb.reconnect	2013-10-31 09:18:35.885407283 +0000
@@ -13,7 +13,14 @@
         config[:flags] = Mysql2::Client::FOUND_ROWS
       end

+      client = nil
+
+      begin
       client = Mysql2::Client.new(config.symbolize_keys)
+      rescue Mysql2::Error
+        sleep 0.3
+        retry
+      end

       options = [config[:host], config[:username], config[:password], config[:database], config[:port], config[:socket], 0]
       ConnectionAdapters::Mysql2Adapter.new(client, logger, options, config)
@@ -250,7 +257,13 @@
       private

       def connect
+        begin
         @connection = Mysql2::Client.new(@config)
+        rescue Mysql2::Error
+          sleep 0.3
+          retry
+        end
+
         configure_connection
       end