Server Cluster Versus Network Load Balancing - HP Rx2620-2 - Integrity - 0 MB RAM Installation And Configuration Manual

Public network
• Each node tracks cluster configuration. Every node in the cluster is aware when another
node joins or leaves the cluster.
• Every node in the cluster is aware of the resources that are running locally and the resources
that are running on the other nodes.
You can create clusters using nodes that have different numbers of CPUs, CPUs with different
clock speeds, or even from nodes running different Integrity platforms. Diverse configurations
are tested, qualified, and certified frequently by HP. The only limitations are that each node must
be an HP Integrity system, and each node must have the same Host Bus Adaptors (HBAs), HBA
drivers, and HBA firmware.

Server Cluster Versus Network Load Balancing

Windows Server 2003 provides two types of clustering services:
Server Cluster
Network Load Balancing (NLB)
Table 1-1 summarizes some of the differences between these two technologies.
Table 1-1 Server Cluster and NLB Features
Server Cluster
Used for databases, email services, line of business
(LOB) applications, and custom applications
Included with Windows Server 2003 Enterprise
Edition and Datacenter Edition
Provides high availability and server consolidation
Can be deployed on a single network or a
geographically distributed network
12 Introduction
One or more public networks can be used as a backup
for the private network and can be used both for
internal cluster communication and to host client
applications. Network adapters, known to the cluster
as network interfaces, attach nodes to networks.
Available only in Windows Server 2003 Enterprise Edition
or Datacenter Edition, this service provides high
availability and scalability for mission-critical applications
such as databases, messaging systems, and file and print
services. The nodes in the cluster remain in constant
communication. If one of the nodes becomes unavailable
because of failure or maintenance, another node
immediately begins providing service, a process known
as failover. Users accessing the service continue to access
it, unaware that it is now being provided from a different
node. Both Windows Server 2003 Enterprise Edition and
Datacenter Edition support server cluster configurations
of up to eight nodes.
Available in all editions of Windows Server 2003, this
service load balances incoming IP traffic across clusters.
NLB enhances both the availability and scalability of
Internet server-based programs such as web servers,
streaming media servers, and Terminal Services. By acting
as the load balancing infrastructure and providing control
information to management applications built on top of
Windows Management Instrumentation (WMI), NLB can
integrate into existing web server farm infrastructures.
NLB clusters can scale to 32 nodes.
NLB
Used for web servers, firewalls, and web services
Included with all versions of Windows Server 2003
Provides high availability and scalability
Generally deployed on a single network, but can span
multiple networks if properly configured