r3042@asus: jeremy | 2005-11-13 01:51:08 -0800

MySQL active? and reconnect!  References #428.
 r3043@asus:  jeremy | 2005-11-13 01:58:28 -0800
 SQLite active? and reconnect!  References #428.
 r3044@asus:  jeremy | 2005-11-13 02:02:27 -0800
 Update CHANGELOG with admonishment regarding avoidance of the log method.


git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@3001 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activerecord/CHANGELOG

@@ -1,6 +1,6 @@
 *SVN*
 
-* When AbstractAdapter#log rescues an exception, attempt to detect and reconnect to an inactive database connection.  Connection adapter must respond to the active? and reconnect! instance methods.  Initial support for PostgreSQL.  [Jeremy Kemper]
+* When AbstractAdapter#log rescues an exception, attempt to detect and reconnect to an inactive database connection.  Connection adapter must respond to the active? and reconnect! instance methods.  Initial support for PostgreSQL, MySQL, and SQLite.  Make certain that all statements which may need reconnection are performed within a logged block: for example, this means no avoiding log(sql, name) { } if @logger.nil?  [Jeremy Kemper]
 
 * Much faster Oracle column reflection.  #2848 [Michael Schoen <schoenm@earthlink.net>]
 

activerecord/lib/active_record/connection_adapters/abstract_adapter.rb

@@ -22,6 +22,12 @@ module ActiveRecord
       include Quoting, DatabaseStatements, SchemaStatements
       @@row_even = true
 
+      @@reconnect_success = 0
+      @@reconnect_failure = 0
+      def self.reconnect_success_rate
+        @@reconnect_success.to_f / (@@reconnect_success + @@reconnect_failure)
+      end
+
       def initialize(connection, logger = nil) #:nodoc:
         @connection, @logger = connection, logger
         @runtime = 0
@@ -40,9 +46,8 @@ module ActiveRecord
       end
 
       def reset_runtime #:nodoc:
-        rt = @runtime
-        @runtime = 0
-        return rt
+        rt, @runtime = @runtime, 0
+        rt
       end
 
       protected  
@@ -100,7 +105,14 @@ module ActiveRecord
         def reconnect_if_inactive!
           if respond_to?(:active?) and respond_to?(:reconnect!)
             reconnect! unless active?
-            raise ActiveRecord::ConnectionFailed unless active?
+            if active?
+              @@reconnect_success += 1
+              @logger.info "#{adapter_name} automatically reconnected.  Success rate: #{'%.2f' % self.class.reconnect_success_rate}%" if @logger
+            else
+              @@reconnect_failure += 1
+              @logger.warn "#{adapter_name} automatic reconnection failed.  Success rate: #{'%.2f' % self.class.reconnect_success_rate}%" if @logger
+              raise ActiveRecord::ConnectionFailed
+            end
           else
             @logger.warn "#{adapter_name} does not yet support automatic reconnection." if @logger
           end

activerecord/lib/active_record/connection_adapters/mysql_adapter.rb

@@ -136,6 +136,25 @@ module ActiveRecord
       end
 
 
+      # CONNECTION MANAGEMENT ====================================
+
+      def active?
+        @connection.stat if @connection.respond_to?(:stat)
+        true
+      rescue Mysql::Error
+        false
+      end
+
+      def reconnect!
+        if @connection.respond_to?(:ping)
+          @connection.ping
+        else
+          @connection.close rescue nil
+          @connection.real_connect(*@connection_options)
+        end
+      end
+
+
       # DATABASE STATEMENTS ======================================
 
       def select_all(sql, name = nil) #:nodoc:
@@ -148,22 +167,10 @@ module ActiveRecord
       end
 
       def execute(sql, name = nil, retries = 2) #:nodoc:
-        unless @logger
-          @connection.query(sql)
-        else
-          log(sql, name) { @connection.query(sql) }
-        end
+        log(sql, name) { @connection.query(sql) }
       rescue ActiveRecord::StatementInvalid => exception
-        if LOST_CONNECTION_ERROR_MESSAGES.any? { |msg| exception.message.split(":").first =~ /^#{msg}/ }
-          @connection.real_connect(*@connection_options)
-          unless @logger
-            @connection.query(sql)
-          else
-            @logger.info "Retrying invalid statement with reopened connection"
-            log(sql, name) { @connection.query(sql) }
-          end
-        elsif 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 update mysql) and read http://dev.mysql.com/doc/mysql/en/password-hashing.html for more information."
+        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."
         else
           raise
         end

activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb

@@ -127,6 +127,19 @@ module ActiveRecord
       end
 
 
+      # CONNECTION MANAGEMENT ====================================
+
+      def active?
+        # TODO: SQLite is an embedded db, it doesn't lose connections,
+        # but perhaps some of its exceptions merit a retry, such as
+        # LockedException.
+        true
+      end
+
+      def reconnect!
+      end
+
+
       # DATABASE STATEMENTS ======================================
 
       def execute(sql, name = nil) #:nodoc: