(ITI310)
SESSIONS 11: Network Load Balancing (NLB)
By Eng. BASSEM ALSAID
“Network Load Balancing (NLB)”
objectives in this session:
- Overview.
- Features in Network Load Balancing.
- Models of Network Load Balancing.
- Installing Network Load Balancing.
- Create a New Network Load Balancing Cluster.
- Add a Host to the Network Load Balancing Cluster.
- Single Copy Cluster.
- Installation of a Single Copy Cluster under Windows 2008 Server.
“Network Load Balancing - Overview”
The Network Load Balancing (NLB) feature in Windows Server 2008 enhances
the availability and scalability of critical mission servers. A single computer
running Windows Server 2008 provides a limited level of server reliability and
scalable performance. However, by combining the resources of two or more
computers running one of the products in Windows Server 2008 into a single
virtual cluster, NLBC can deliver the reliability and performance that Web
servers and other mission-critical servers need.
All versions of Windows Server 2008 supports Network Load Balance (NLB) for
a group of 2 to a maximum of 32 nodes (We consider each server in a cluster as
a node).
“Network Load Balancing - Overview”
The diagram above shows two connected Network Load Balancing clusters.
The first cluster consists of two hosts and the second cluster consists of four
hosts. This is one example of how you can use NLBC.
“Network Load Balancing - Overview”
In a Network Load Balancing configuration, a virtual IP address is assigned to
each group. When a client invokes a service from the cluster, the request will
be translated to one of the real addresses of the cluster servers depending to
both: original settings and servers availability.
“Features in Network Load Balancing”
NLB includes the following features:
– Scalability.
– High-availability.
– Manageability.
– Ease of use.
“Models of Network Load Balancing”
Each server in a Windows Server 2008 NLBC could have two network adapters.
This is recommended for maximum performance. In this case a first adapter is
used for communication between cluster nodes and the other for
communication with the clients. Generally, there are four Network Load
Balancing models:
– Unicast with Single Network Adapter.
– Unicast with Multiple Network Adapters.
– Multicast with Single Network Adapter.
– Multicast with Multiple Network Adapters.
“Configuring Port”
Network Load Balancing is configured on a port by port basis or by range of
ports. There are 3 options for controlling traffic:
• Single Host: Traffic is forward to a node in the cluster.
• Multiple Hosts: Traffic is distributed between the nodes in the cluster.
• Disabled: No Action and no filter.
Practice I:
1. Installing Network Load Balancing.
2. Configuring NLB under Windows Server 2008.
3. Adding Nodes to NLB.
“Single Copy Cluster”
A single copy cluster (SCC) is a mailbox server cluster that uses shared storage
configuration in a failover cluster to allow multiple servers to manage a single
copy of storage groups.
If the node running a mailbox server cluster has problems, the mailbox server
cluster goes offline briefly and let another node takes control of the mailbox
server in the cluster. This process is called failover.
Administrator can manually move a server mailbox clustered between nodes in
a cluster. This process is called a transfer process.
“Installation of a Single Copy Cluster under
Windows 2008 Server”
Main phases of Single Copy Cluster deployment:
• Configuring storage.
• Configuring Network.
• Training the cluster.
• Network configurations clusters.
• Validate the failover cluster.
THANKS