Hi everyone,

I am toying with the idea of using a load balancer (css11501) to balance traffic request coming in from my web servers to the database, for read and write.

The database servers will be VMs seating across various physical nodes, and will have a shared database store over iSCSI.

Is that feasible?

GFS handles the file level locking... but without MySQL cluster, will this work?

Load Balancing is always a good idea if something is working it's a.. feet of but when I think about your setup I would not do it.
Like I see it and I say you to the bottleneck for mysql (or db servers in generel) is either the memory or the diskaccess. Memory is nice but also high in price and you would nearly need enough to have all the databases inside memory.
When it comes to disk I think you totaly give in to problems. If you have all MySQL VM's read from the same medium i'd say your screwed.
None the less if you just mount the db data readonly I dare to say it'll work. But there sure be cases where you'll get errors or old data for a statement.

I would look into some good replication strategy and loadbalance this or pay a huge amount of money for a lot of memory.

Hi there,

so you're saying if I want to scale my database, I should either:

1) get lots of memory with faster disk access

2) Or use replication and scale the read only

If I am just thinking about HA and data backup, will having 2 nodes (HA) sharing a shared storage (say iSCSI) for shared data store be suitable? If I virtualize it?

Or should I just stick to physical?

I guess for HA a shared storage sure is an option and sure is the best failover method (you just switch progamm but the data remains the same and is up to date). It does not matters if virtual or physical (pretending you have the two on diffrent machines).

If you go just for backup it does not really matter if shared on physical or virtual it's the same mechanic you get your data from...

Dunno whats your goal your after but in my opionion virtual is only for CPU and maybe MEM intensive solutions. When it goes down to the hardware it's just bound to it like every other HA solution...

Hi,

I played some time ago with the idea of load balancing MySQL also. Our setup is using two nodes, virtual machines in VMWare ESX. I use heartbeat for HA. After some trial I decided to go with master-master replication on MySQL databases and that works like a charm and has been running for about three months now without any problems or load on the server/cpu/memory. With the first trials on load balancing I got heavy memory usage and after trying master-master replication I stuck with that.

Kind regards,

Eric