MySQL Python Replicant
======================

The MySQL Python Replicant is a library for controlling and
maintaining large deployments of MySQL servers. The library provide
classes and functions to be able to fetch data from server, redirect
servers, and in general control a replication setup.


Testing
-------

The following command will execute the tests for the library.

    python setup.py test

The test suite currently does *not* use a mock database connection, so
for the server tests to work, you have to have a set of database
servers configured.

I have done the following to set up four servers on my local machine:

1. Edit /etc/mysql/my.cnf and adding the following lines:

      [mysqld_multi]
      mysqladmin      = /usr/bin/mysqladmin
      user            = root

      [mysqld1]
      !include /etc/mysql/mysqld1.cnf
      [mysqld2]
      !include /etc/mysql/mysqld2.cnf
      [mysqld3]
      !include /etc/mysql/mysqld3.cnf
      [mysqld4]
      !include /etc/mysql/mysqld4.cnf

   The section headers are necessary for mysql_multi to recognize the
   servers.

2. Create one configuration file for each server, for example:

      [mysqld1]
      server-id       = 1
      pid-file        = /var/run/mysqld/mysqld1.pid
      socket          = /var/run/mysqld/mysqld1.sock
      port            = 3307
      datadir         = /var/lib/mysql1
      log-bin         = /var/lib/mysql1/mysqld1-bin.log
      log-bin-index   = /var/lib/mysql1/mysqld1-bin.index
   
3. Start the servers.

      $ sudo -umysql mysqld_multi start

4. Edit the <root>/tests/deployment/<deployment file> file so that the
   information is correct.

5. Create a 'test' database where all necessary tables will be
   created.

6. It is necessary to create a user mysql_replicant@localhost on each
   server and grant them full access. The following commands (executed
   on each server) should solve this.

       CREATE USER mysql_replicant@localhost;
       GRANT ALL ON *.* TO mysql_replicant@localhost WITH GRANT OPTION;

7. Run the tests.

If you have apparmor active (I had), you have to edit the apparmor
file to avoid an error. I did the following change to
/etc/apparmor.d/usr.sbin.mysqld:

    --- usr.sbin.mysqld.orig        2010-07-04 09:16:51.218593117 +0200
    +++ usr.sbin.mysqld     2010-07-04 09:16:14.286592607 +0200
    @@ -23,6 +23,7 @@
       /etc/mysql/conf.d/ r,
       /etc/mysql/conf.d/* r,
       /etc/mysql/my.cnf r,
    +  /etc/mysql/mysqld[0-9].cnf, r
       /usr/sbin/mysqld mr,
       /usr/share/mysql/** r,
       /var/log/mysql.log rw,
    @@ -33,6 +34,14 @@
       /var/log/mysql/* rw,
       /var/run/mysqld/mysqld.pid w,
       /var/run/mysqld/mysqld.sock w,
    +  /var/log/mysql[1-9].log rw,
    +  /var/log/mysql[1-9].err rw,
    +  /var/lib/mysql[1-9]/ r,
    +  /var/lib/mysql[1-9]/** rwk,
    +  /var/log/mysql[1-9]/ r,
    +  /var/log/mysql[1-9]/* rw,
    +  /var/run/mysqld/mysqld[1-9].pid w,
    +  /var/run/mysqld/mysqld[1-9].sock w,

       /sys/devices/system/cpu/ r,
     }


Installation
------------

To install the library

    python setup.py install