[Serusers] Re: SER database sharing

[Andreas Granig]

Juha Heinanen wrote:
> which version of mysql cluster you are using?  last time i tested with
> 4.1.15, after disconnecting ethernet cable from one of the two database
> hosts of the cluster, it took more than one minute before cluster became
> operational again (now using only one database host).

4.1.x was quite faulty, so I started with 5.0.15 and now use 5.0.22. I
use two nodegroups with two nodes each, and each node is connected to
the LAN with two NICs in active/backup bonding mode, so disconnecting
one cable doesn't harm.

If you shoot one node in this setup, the cluster stays operational. If
two nodes from different node groups get down simultaneously (in case of
a power failure of one of the two UPS for example), it also may take up
to a minute until the cluster is up again. If two nodes of one node
group get down, then the cluster obviously fails.

This setup works fine for me, because you can always take one node at a
time down for maintenance without effecting the system.

Andy