mysqld on drawable.gnome.org

[Owen Taylor <otaylor redhat com>]

I've gone ahead and set up MySQL on drawable.gnome.org. Notes:

 * mysqld configuration is as in my other mail. For now I have
   innodb_file_per_table on.

 * /var/lib/mysql is on a 128GB lvm partition. This partition is
   shared with /var/lib/mysql-backup, so the possible database size
   is about half that. (Current bugzilla is about 8GB.) There's
   room on the local disk for enlarging the partition - the machine
   has ~270GB of total disk space. I kept the partition "small" for
   now for flexibility.

 * Port 3306 is open on the backend network (and only on the backend 
   network)

 * Access is granted to bugzilla bugzilla-web-back and 
   bugzilla label-back to the bugs database, as per:
 
http://www.bugzilla.org/docs/3.4/en/html/configuration.html#install-setupdatabase-adduser

   The password is the same as for the existing bugzilla database and
   can be found in /home/admin/bugzilla/private.pl.
 
   I tested that I could create a bugs database from bugzilla-web, then
   dropped the database again.
 
 * Database backup is set up the same way as on button, by copying
   the tables using mysqlhotcopy to /var/lib/mysql-backup, and then 
   only /var/lib/mysql-backup is rsync'ed to a machine that is
   tape backup.
   
   IMPORTANT FIXME: this doesn't work for InnoDB tables. Options:

    http://www.innodb.com/products/hot-backup/order/
    Closed source, $$$$

    http://www.percona.com/docs/wiki/percona-xtrabackup:start
    Don't know if this is production ready or not

    mysqldump
    gzip'ed mysqldump is suprisingly reasonable for snapshotting

   With whatever option we take, copy-db.py has to be enhanced to detect
   InnoDB tables and copy them appropriately. This needs to be fixed 
   before going into production.

 * Database that shouldn't be backed up need to be added to the
   mysql_copy_db_exclude variable in the puppet configuration for the
   drawable node.