MySQL server has gone away fix

connection_fix.rb

# If your workers are inactive for a long period of time, they'll lose
# their MySQL connection.
#
# This hack ensures we re-connect whenever a connection is
# lost. Because, really. why not?
#
# Stick this in RAILS_ROOT/config/initializers/connection_fix.rb (or somewhere similar)
#
# From:
#   http://coderrr.wordpress.com/2009/01/08/activerecord-threading-issues-and-resolutions/
#
# Modified by Eric Lindvall <eric@sevenscale.com> to prevent a reconnect from happening
# during an open transaction.
#


class ActiveRecord::ConnectionAdapters::MysqlAdapter
  alias_method :execute_without_retry, :execute

  def execute(*args)
    retried = false
    execute_without_retry(*args)
  rescue ActiveRecord::StatementInvalid => e
    if !retried && open_transactions.zero? && e.message =~ /^Mysql::Error: (MySQL server has gone away|Lost connection to MySQL server at|query: not connected:)/i
      retried = true
      warn "Server timed out, retrying"
      reconnect!
      retry
    else
      raise
    end
  end
end