|One Quad CPU Quad Cored or Two Dual CPU Dual Cored Servers?|
Which is better?
Any truth to this?
Running both Apache and SQL on one server with quad CPU’s, Quad cored (one 16 CPU server) with each service running on a separate dedicated 15,000RPM SCSI drive would perform better than running my current configuration of two separate servers for each service, cross connected, which are running on dual CPU’s dual cored (two 4 CPU servers).
With the argument being that by removing the cross connect, this will keep all data on the same mother board and not going in/out of the NIC… and by using dedicated drives for the two main services, I will get better performance.
Hence, by going to this configuration, I can afford to buy two servers in two different DC’s and load balance between the two, giving me redundancy that I very much want after hearing of the ThePlanet mishap (it is a warning sign) in Houston.
Thanks for your input.
Your web server software and your DB shouldn't be on the same server, not only for performance reasons, but also for security reasons. If someone hacks your web server they will have access to your DB as well.
For performance, it is much better to have them separated out as it will lead to a much easier upgrade solution. Let's say you double your traffic, your DB will be able to keep up with the increase, but your web server won't. All you need to do is add in another load balanced web server and you are good to go.
We've done pretty much what you're describing, but completely in a Windows environment. The primary server serves pages significantly faster with the db on the same motherboard and the backup box is always there for backup. With one server it stands to reason that site failure is half as likely as with 2.
I understand the security implications, but if 1 box is compromised, all servers on the LAN are suspect anyway. I'd rather be able to replace the complete system in one box.
As for upgradability, that could be a problem in some instances, but my server CPU averages less than 4 percent usage. By the time I outgrow this type of set up I will be able to afford my own datacenter.
Go for redundancy, ie 2 servers. 16 CPUs (or cores) in one server might be hard to load fully in real life scenarios, so you might end up with lots of spare CPUs that you can't take advantage off because you are disk limited. Also having too many CPUs (especially Intel ones - AMD uses hypertransport which is much better than bus approach Intel currently uses, but this will change later this year) results in increased overheads, so I think overall you will gain more by having 2 servers, though you need to factor in increased hosting costs.