- Server Cluster
- Network Loadbalancing
A Server Cluster is a collection of independent servers that together provide a single highly available platform for hosting application.
Network Load Balancing:
- With load balancing, a single device (a network client) sends traffic to any available node in the load-balanced group of nodes.
- Load balancing uses heartbeat traffic as well but, in this case, when a node comes offline, the “load” is recalculated among the remaining nodes in the group.
Cluster requirements:
- Two Servers with Same configuration
- Two network cards in each server
- SAN storage
- SAN Switch
- Windows server 2003 Enterprise or Data center edition OS
- Windows NT 4.0 Enterprise Edition supported 2 Node cluster
- Windows 2000 Data canter Server supported up to 4 Node cluster
- In Windows 2003 Enterprise & Data center editions supports up to 8 node Clustering.
- In Windows 2003 Enterprise & Data center editions Supports up to 32 node in Network balancing.
- In Windows 2008 Enterprise & Data center editions supports up to 16 node Clustering.
- For more Details : http://support.microsoft.com/kb/288778
Quorum:
Quorum Types:
Standard Quorum :
Each member connects to the shared storage via some type of interconnect (e.g. SCSI or Fiber Channel).
A MNS quorum is a single quorum resource from an Server cluster perspective. The data is actually stored by default on the system disk of each member of the cluster.
- Failover is the act of another server in the cluster group taking over where the failed server left off.
- Failback is the capability of the failed server to come back online and take the load back from the node the original server failed over to
- Active/Active
Two nodes providing services to the network clients. That’s 100 percent of served resources. If one server fails, then the clients will only have one server in which to access and that would cut the percentage to 50 percent
- Active/Passive
Active/Passive is defined as a cluster group where one server is handling the entire load and, in case of failure and disaster, a Passive node is standing by waiting for failover.