Hello!
I received a lot of great replies to my original post, and have responded to
them, but just now realized that I forgot to cc the list, so please let me
publically thank Geert, Andrew, Matthew and Casey for their input!
This list is a fantastic source of information and advice about MySQL
Cluster!
Mike van Lammeren
On Wed, Sep 30, 2009 at 6:33 PM, Mike van Lammeren <mike@stripped>wrote:
> Hello!
>
> I'm in the architecture/detailed design stage of a project that at launch
> will require around a dozen servers. The current plan has 4 servers for a
> MySQL Cluster. The cluster will consists of 2 servers running MySQLD and
> NDB_MGMD, and two NDB nodes. (A third NDB_MGMD server is running on another
> box.)
>
> The problem is that we want high availability for all of our servers. For
> example, the VoIP servers and WWW servers are all running behind a
> load-balancer, plus a hot spare load-balancer, to give n+1 servers for each
> function. I would love to add another pair of load-balancers for the
> cluster, so that both servers running MySQLD could be put to use, but at
> this point, there is no budget for a second pair of load-balancers. That
> leaves me with the option of running a single MySQLD server, and leaving the
> other as a hot spare.
>
> An alternate configuration could see half the VoIP servers connecting to
> one MySQLD server, and half connecting to the other. Ditto for the WWW
> servers, media servers, etc. Unfortunately, this does not provide the high
> availability we need, since half the servers would go down in the event that
> one of the MySQLD servers dies.
>
> So, a radical(?) solution occurred to me just now. What if we spread the
> MySQLD servers around to all the other servers? In other words, each VoIP
> server, WWW server, etc., would also be running a MySQLD server. The
> applications on the servers would talk exclusively to MySQLD on the same
> box. We would then only need two machines in the cluster for NDB nodes. This
> would have the added benefit of cutting local network traffic in half.
>
> What do you think? Is this crazy? Am I missing something?
>
> Mike van Lammeren
>
>
