asked on

Cluster vs load balancing (windows 2008 and SQL 2008)

I am quite confused between the service cluster and the load balancing. Is there any pro of Cluster over the load balancing since as I know actually load balancing can do cluster also? E.g I have 3 machines with load balancing A, B, C. If B machine is down, the clients still switch to A or C which is the cluster purpose and provide high availability. I don't understand why need service cluster since it is active-passive only. I think it is just used in several different resources sharing in different machines environment. or application does not support load balancing.

Is there any called load-balanced cluster? Does it combine service cluster and load balancing or it is a type of load-balancing only? But really don't understand the pro of combining 2 services

Another question is MS SQL 2008 supports load balancing? If so, SQL 2008 has specify setting to set the load balancing or just replication? No need to set the NLB in 2008?

ASKER CERTIFIED SOLUTION

chapmandew

membership

This solution is only available to members.

To access this solution, you must be a member of Experts Exchange.

Start Free Trial

SOLUTION

deroyer

membership

This solution is only available to members.

To access this solution, you must be a member of Experts Exchange.

Start Free Trial

Torus

ASKER

Well. I understand that the both NLB and cluster service uses same mechanism virtual IP to connect to the server. But really don't understand if I use IIS which supports load balancing, it is no reason to use cluster since load balancing includes failover part. And as I said in my question, I just find that the only reason to use cluster because the software doesn't support LB or different resources across different machines forms a cluster to provide transparent to user to access the resources

Also what is load balanced cluster?

deroyer

A load balanced cluster can either be just a fancy way of saying cluster or you can with some apps create VIPs that point to cluster VIPS and have multiple clusters. What I mean is that technically you could create a cluster of clusters if you were so inclinded, but I have never done it.

As far as this statement goes the primary thing is to have redundancy where posible... If you have multiple web application servers that all connect to SQL then either could be a viable option. It really is just a matter of symantecs at that point...
"But really don't understand if I use IIS which supports load balancing, it is no reason to use cluster since load balancing includes failover part. And as I said in my question, I just find that the only reason to use cluster because the software doesn't support LB or different resources across different machines forms a cluster to provide transparent to user to access the resources"

Torus

ASKER

Sorry, after your explanation, I still can't got that why use cluster if an application supports load balancing or the using nature is totally different?

deroyer

OK Cluster fails over... Load balancing spreads the load...