Cluster/cloud/galera support

[Kiu345]

Hello,

 

I'm currently planing a new webserver cluster for a php based portal. ATM, im using froxlor on a single machine and let it generate the files on a mirrored drbd-ocfs2 device to the other nodes.

Because of the reason that I plan to create the new cluster on a template based "create x nodes, group them together and have fun" style, this is not the best approach I think. Tested some solutions, and it seems a maria-galera-cluster would be a simple and stable db solution for that.

 

So now why I am posting that here? Because it would need some little changes (or better, things you should not try to break in future development) to support this:

• Galera only supports InnoDB (ATM), so I have to convert all the tables to that engine first. That should not be a problem as long as you don't need any special MyISAM features now/in the future. Maybe there could be an install option to select the db engine in which the tables are created?
• If the cron job could remember the name of the machine (or another identifier) and check for lastrun on that name-timestamp-combination, it would be possible to generate the files on all nodes without the need of a cluster fs (for that) because the script knows if it has been run on THIS machine since the last config change.
• MySQL user/structure handling should always be done with GRANT/SET... statements and not by altering the mysql.* tables directly (those changes would not be replicated because those are myisam tables).

AFAIKS, this should be not a big task and I could help if you like.

 

Greeting

(and hope you understand my long-time-not-used english writing skills ;-) )

 

[d00p]

Our future version 0.99 will have multi-server-support anyway until then i cannot promise that things won't change. And sorry, but only because "Galera" needs InnoDB i won't change all the database-structures and tables (we're using PDO in 0.99 - so you can decide what you need later).

Also, I'm pretty sure we're not querying any mysql.* tables directly

[Kiu345]

Our future version 0.99 will have multi-server-support anyway until then i cannot promise that things won't change. And sorry, but only because "Galera" needs InnoDB i won't change all the database-structures and tables (we're using PDO in 0.99 - so you can decide what you need later).

Also, I'm pretty sure we're not querying any mysql.* tables directly

 

There is no need to change the struture, afaiks you have primary keys and stuff in the model. The only thing that needs to be done is not to use "ENGINE=MyISAM" to let mysql use its default engine on the end of the create table - thats all ;-)

[d00p]

I know that, but "create the tables" is not all, need to update also...and for what? Only because "Galera" wants that? For 99,9% this change is unnecessary