Addressing your risks
Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2
Addressing your risks
A principal goal of Network Load Balancing is to provide increased reliability. A cluster of two or more computers ensures that if one computer fails, another computer is available to continue processing client requests.
However, Network Load Balancing is not designed to protect all aspects of your workflow in all circumstances. For example, Network Load Balancing is not an alternative to backing up data. Network Load Balancing protects only the availability of data, not the data itself. Also, it does not guard against a power outage that would disable the entire cluster.
Windows Server 2003, Standard Edition ; Windows Server 2003, Enterprise Edition ; and Windows Server 2003, Datacenter Edition , have built-in features that protect certain computer and network processes during failure. These features include disk mirroring (RAID Level 1) and disk striping [AMC25A] with parity (RAID Level 5). When planning your Network Load Balancing environment, look for places where these features can help you in ways that Network Load Balancing cannot.
The following table lists common points of failure in a Windows Server 2003, Standard Edition ; Windows Server 2003, Enterprise Edition ; or Windows Server 2003, Datacenter Edition , environment, and describes whether the point of failure can be protected, either by Network Load Balancing or by other means.
These features include RAID-1, disk mirroring, RAID-5, and disk striping with parity.
| Failure point | Network Load Balancing solution | Other solutions |
|---|---|---|
Network hub |
n/a |
Redundant networks |
Power outage |
n/a |
|
server connection |
Failover |
n/a |
Disk |
Failover |
Hardware or software RAID, to ensure against the loss of data on a specific computer and to provide uninterrupted service |
Other server hardware, such as CPU or memory |
Failover |
Spare components, such as motherboards and SCSI controllers (any spare components should exactly match the original components, including network and SCSI components) |
server software, such as the operating system or specific applications |
n/a |
server clusters (only computers running Windows Server 2003, Enterprise Edition , or Windows Server 2003, Datacenter Edition ) |
IP-level failures, such as IIS service interruptions |
Failover |
n/a |
WAN links, such as routers and dedicated lines |
n/a |
Redundant links, to provide secondary access to remote connections |
Dial-up connection |
n/a |
Multiple modems |
Application or Service failure |
n/a |
Microsoft Application Center, available as a separate product, contains tools to monitor specific applications and services. |