Building a cluster of servers, need networking help.

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InorganicMatter

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I will probably have 3-4 servers in my cluster. However, I do not think that 1gb ethernet will be fast enough for our company's needs. I have been considering Fibre Connect (QLogic). What would you guys suggest I use? Oh yeah, the motherboard has an array of PCI, PCI-X, and even a few PCIe connectors on it, so that shouldn't be a problem.
 
Well, I'm just the little guy who builds the computers. The head honcho of the IT department is the one that figures out all the details. Best I can make out, he plans to "cluster" the servers together so that the cluster acts like one giant machine. A request gets sent to the servers, if server 1 is too busy, it will forward the request to server 2. If server 2 is too busy, it will forward the request to server 3, and so forth.
 
A special web-based program our company uses (or will use). It has all the client's data and processes all the client's requests, so as to take the load off of the client's computers. But mostly email and databases I guess. Databases more so.
 
Gigabit with jumbo frames is plenty fast enough for most every enterprise application. Even if you went "fiber" that is not necessarily going to be any faster than GigE copper in most applications unless you've got the equipment and the ports to go 10G.

If they are "home-brew" servers you will want to have one or two network cards (if two then in load-balancing mode via manufacturer drivers like intel's ProSET or Broadcom's BACS) for networking. I'd personally recommend getting some of intel's Pro1000 server nic's, especially if you are using jumbo frames on your network, but that's simply opinion.

On top of that you'll want to have one network card that you can dedicated solely to cluster operations. The cables from the cluster nic's should all go into a dedicated switch - this switch does not have to be connected to the live network and in fact it's better if it isn't -- the cluster NIC's only need to communicate with eachother after all.

Cluster NIC's do not send all that much data and can be FastE unless you've got a few extra GigE NIC's laying around to dedicate to that.

The software will do the rest.
 
Then Gb is fine. If it's some large cluster doing parallel processing then network becomes a bottleneck. You are talking about either a load balancing or failover cluster...neither of which requires more than Gb normally.
 
Your GigE speeds are going to also depend upon what you're putting them into. I believe the 'server' type of cards were mentioned. That means 64bit PCI versus 32bit PCI. 32bit cannot make use of all the available bandwidth in GigE NICs. Keep that in mind.

I also agree on isolating that traffic to a point. If you're going to use a switch that's new and fast enough it will have the backplane to handle whatever traffic you send it's way. But ultimately if total bandwidth is that critical then physically seperate the segments as well as seperate them logically.
 
Now, since the guys have addressed most of the network side.

You said.
"A special web-based program our company uses (or will use). It has all the client's data and processes all the client's requests, so as to take the load off of the client's computers. But mostly email and databases I guess. Databases more so."

You haven't specified which platform. Lets take windows. Windows 2003.

IIS is easily clusterable. (for your website).

Email (exchange) is not so. Even harder for databases (SQL). Neither support active active clustering (officially from microsoft) and even in an active/passive cluster, require some sort of shared storage (separate array, SAN or ISCSI)

There is much much more than just getting 4 identical boxes, networking them together and hoping there is a way to cluster them easily.

Tell us more in detail of what you want to do...
 
Well if these are new servers, I am going to guess that you are going to be using Server 03 or Linux...the way you are talkling...I am going to drill that down even further to guess Server 03.

So you have 4 boxes running 03...just run Network Load Balancing Manager to configure the four servers as a Network Load Balancing cluster.

What some one said before is correct to truly cluster boxes you need additional hardware and that is probably not something you or your boss wants to deal with, especially if all of the funds that were allocated on the project have already been spent :D

You could also try round robin DNS...which works until one fails, at which point clients are still directed to the broken box...probably not the best idea :rolleyes:

Here is a brief description of Network Load Balancing:

Clustering allows you to combine application servers to provide a level of scaling, availability, or security that is not possible with an individual server. Network Load Balancing distributes incoming client requests among the servers in the cluster to more evenly balance the workload of each server and prevent overload on any one server. To client computers, the Network Load Balancing cluster appears as a single server that is highly scalable and fault tolerant. The Network Load Balancing deployment process assums that your design team has completed the design of the Network Load Balancing solution for your organization and has performed limited testing in a lab. After the design team tests the design in the lab, your deployment team implements the Network Load Balancing solution first in a pilot environment and then in your production environment.


...of course you have to be running '03 to really take advantage.... ;)
 
Can't you only cluster two Server 2003 servers together??... I know that's the case with 2000 Advanced Server.
 
enforcer17 said:
Can't you only cluster two Server 2003 servers together??... I know that's the case with 2000 Advanced Server.
Click to expand...

It was increased with 2003 to 8 nodes I believe. But you still need to use Server 2003 Enterprise edition.
 
As it was mentioned earlier, for a cluster to function optimally you're also going to need an enterprise level storage fabric to ensure that each cluster member has access to the same data at the same time. This pretty much requires a SAN especially for what you want to do with it.

Also, how many people are we talking here? And what nOS? (2K3? Linux?)

Having a cluster is fine and dandy but is there an actual need there?
 
Not for an NLB cluster, which from his description, is what he's looking to do.
 
Yeah, if it's a web / IIS based application with a DB backend, the web servers can all be clustered using NLB. I just added 4 Server 2003 Web Editions to my 3 2000 Advanced Server NLB cluster. Runs like a champ (100mbit). They all connect back to our quad xeon db server. Web clustering - where a request will go to any available web server - is MUCH easier than DB / Exchange clustering. It sounds like you just need web / NLB clustering, which is trivial in comparision to actual clustering. two 100mbit connections (one for cluster heartbeat traffic, the other to serve requests) will work absolutely fine for an 8 member web cluster, let alone an NLB cluster with only 4 nodes.
 
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