Run multiple mysql instances in mysql

Question

I want to use MySQL server on two different ports on the same machine. I have made two separate config files. When I'm trying to connect to the MySQL server on the second port I defined then I can't connect. The OS running MySQL is Windows Vista. I also tried to start mysqld from command line after specifying port.

This is the sample file I have changed for MySQL server to read from two different ports:

# CLIENT SECTION
# ----------------------------------------------------------------------
#
# The following options will be read by MySQL client applications.
# Note that only client applications shipped by MySQL are guaranteed
# to read this section. If you want your own MySQL client program to
# honor these values, you need to specify it as an option during the
# MySQL client library initialization.
#
[client]

port=3306

[mysql]
mysql-path="C:\Program Files\MySQL\MySQL Server 5.1\bin"
default-character-set=latin1

[client]

port=3307

[mysql1]
mysql1-path="C:\Program Files\MySQL2\MySQL Server 5.1\bin"
default-character-set=latin1

# SERVER SECTION
# ----------------------------------------------------------------------
#
# The following options will be read by the MySQL Server. Make sure that
# you have installed the server correctly (see above) so it reads this 
# file.
#
[mysqld]
mysqld-path="C:\Program Files\MySQL\MySQL Server 5.1\bin\"

# The TCP/IP Port the MySQL Server will listen on
port=3306

#Path to installation directory. All paths are usually resolved relative to this.
basedir="C:/Program Files/MySQL/MySQL Server 5.1/"

#Path to the database root
datadir="C:/ProgramData/MySQL/MySQL Server 5.1/Data/"
#
server_id=1

[mysqld1]
# The TCP/IP Port the MySQL Server will listen on
port=3307
server_id=2
mysqld1-path="C:\Program Files\MySQL2\MySQL Server 5.1\bin\"

#Path to installation directory. All paths are usually resolved relative to this.
basedir="C:/Program Files/MySQL2/MySQL Server 5.1/"

#Path to the database root
datadir="C:/ProgramData/MySQL2/MySQL Server 5.1/Data/"
#
# The default character set that will be used when a new schema or table is
# created and no character set is defined
default-character-set=latin1

# The default storage engine that will be used when create new tables when
default-storage-engine=INNODB

# Set the SQL mode to strict
sql-mode="STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION"

Answer 1

The installation procedure differs slightly based on your server/operating system.

For linux you might find this useful - http://code.openark.org/blog/mysql/manually-installing-multiple-mysql-instances-on-linux-howto

Google it and you might find for others too.

Answer 2

better to use mysql_multi http://www.pythian.com/blog/using-mysqld_multi-to-manage-multiple-servers/

copies of configs are dirty hack imho

Answer 3

You need to also specify a different datadir (i.e. the directory which contains the database files) on the command-line. You cannot open the same databases in different instances, as they would lock each other and/or cause data-corruption.