[Linux-cluster] MySQL Cluster

[Tiago Cruz]

Hello Gordan

Thanks for your attention and sorry by my late, I spend some days
reading/ testing about this subject before I come to you again :)


On Fri, 2008-04-25 at 01:02 +0100, Gordan Bobic wrote:

> Last time I tried using MySQL Cluster it was unacceptably slow. It 
> wasn't really a workable solution. MySQL replication was a much better 
> option.

Ok, good to know!


> You could use DRBD in primary-primary mode with GFS on top and external 
> locking in MySQL. It would work, but performance would suffer a great 
> deal. It depends on what kind of throughput you need.

Yes... I'm not tried this yet, maybe should I try... I'll get some good
redundancy of servers!

But, I was researching about mysql "master -> master" that should be a
good throughput/ redundancy. Did you already use this? 


> Depending on your application, you could use something like MySQL 
> round-robin replication. In that configuration, MySQL servers replicate 
> in a ring.

The Ring, it's some like this: (?)

A -> B -> C -> A

Right? So... If I lost the "B" server... "A" will can't sync "C"?

Sound like dangerous for me :-)


>  The downside is that there is a race condition inherent in 
> the design, if you think about it carefully. (DRBD+GFS+ MySQL with 
> external locking doesn't suffer the race condition.) If this potential 
> race condition is not a concern for your application, then performance 
> wise, it is likely to be the optimal solution for you. Since you said 
> that fail-over is not an option for you, I am assuming that the load you 
> plan to put through it is too great for one server to handle (I have 
> seem low-spec servers with MySQL churning out 100,000+ queries per 
> second when tuned up correctly). If you are dealing with this sort of 
> load, DRBD+GFS+MySQL isn't going to cut it and round-robin replication 
> with the mentioned race condition is pretty much your only option.

Well, this LAMP-HA will be hands a lot of end-user application, like
Wordpress, Joomla, phpBB and etc, so I don't know if I'll have race
condition :-(

Thanks!
-- 
Tiago Cruz
http://everlinux.com
Linux User #282636