Question

What I am surmising is that mysql2 does not default to a TCP connection protocol when I remove the socket parameter. Do you guys agree? Any GEM suggestions?

I can connect via the mysql command line. So yep all configured from a mysql point of view.

This line connects nicely: “mysql -P 3406 -u userid -p –protocol=TCP -h localhost”
Enter password:

Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 77402
Server version: 5.0.77-log Source distribution

Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> show databases;
+---------------------+
| Database            |
+---------------------+

database.yml

svc_development:
    adapter: mysql2
    encoding: utf8
    database: my_db
    username: userid
    password: apasswd
    host: localhost
    port: 3406  

The port is correct for this instance. I am connecting to this database via SSH tunnel “-L 3406:host:3306”
I looked at themysql2 code, it does not take a protocol parameter. It just uses socket.

Model: looky_loo.rb

class LookyLoo < ActiveRecord::Base
    self.abstract_class = true
    establish_connection  "svc_development"
end

From Rails console

from script/rails:6:in `<main>'ruby-1.9.2-p136 :002 > LookyLoo.all
Mysql2::Error: Access denied for user 'userid'@'localhost' (using password: YES)
    from /Users/michael.pechner/.rvm/gems/ruby-1.9.2-p136@amqp/gems/mysql2-0.2.7/lib/mysql2/client.rb:42:in `connect'
    from /Users/michael.pechner/.rvm/gems/ruby-1.9.2-p136@amqp/gems/mysql2-0.2.7/lib/mysql2/client.rb:42:in `initialize'
    from /Users/michael.pechner/.rvm/gems/ruby-1.9.2-p136@amqp/gems/mysql2-0.2.7/lib/active_record/connection_adapters/mysql2_adapter.rb:14:in `new'
    from /Users/michael.pechner/.rvm/gems/ruby-1.9.2-p136@amqp/gems/mysql2-0.2.7/lib/active_record/connection_adapters/mysql2_adapter.rb:14:in `mysql2_connection'
    from /Users/michael.pechner/.rvm/gems/ruby-1.9.2-p136@amqp/gems/activerecord-3.0.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:229:in `new_connection'

Answer 1

In mysql localhost is “magic” it means use the socket. Try using 127.0.0.1 instead.