This document provides an overview of Windows Server 2008 R2 Failover Clustering and Network Load Balancing. It discusses what a cluster is, why they are used, and cluster terminology. It also covers the software and hardware requirements for failover clustering, and the process of validating and creating a cluster. For network load balancing, it describes how load balancing works, deployment requirements, and options for configuring host parameters and port rules.

2. Windows Server 2008 R2 Failover
Clustering and Network Load
Balancing
October 25th 2009

3. Agenda
Introduction to Clustering
What is cluster
Why use cluster
Cluster common terminology
What is High Availability
Hardware / Software Requirements
Cluster Validations / Cluster Creations.
Introduction to WNLB
Overview of Network Load Balancing Clusters
Configuring a Network Load Balancing Cluster
Maintaining a Network Load Balancing Cluster
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4. What Are Clusters?
A cluster is a group of computers and storage devices that work
together and that you can access as a single system
The individual computers in a cluster act together to provide:
• Distribution of processing load
• Automatic recovery from failure of one or more components
in the cluster
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5. Discussion: Why Use Clusters?
Can you realize a return on investment when you
deploy an expensive cluster?
What issues might you encounter when network
services are not available?
Which services would you make highly available?
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6. Clustering Terminology
Term Description
Node A server that participates in a cluster
Resource A device or service hosted on a cluster and
accessed directly or indirectly by the application
or end user
Failover An highly available clustering type with
clustering resources owned by a single server at a time
Load balancing A clustering type that distributes processing
across a number of nodes
Fault tolerant A key component of clusters that withstands
problems in hardware or software while
continuing to operate
Planned The amount of time an application is unavailable
downtime due to an update or other maintenance
Unplanned The critical amount of time an application is
downtime unavailable due to a component failure

7. What is High Availability?
The world is now a 24/7 global marketplace
Systems must be online or customers are lost
Goal of high availability (HA) is to keep
systems, applications, services, email, databases, f
iles & printers readily available
Every business now has high availability needs
Uptime Percentage Maximum downtime per year
99.999 5 minutes
99.99 52 minutes
99.9 8.7 hours
99 3.7 days
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8. Why is HA Important?
Server downtime is unavoidable
Keep your business running and competitive
Servers may go offline due to
Maintenance
Upgrade
Software or Hardware
Update
Hot Fix, Security Patch
Accident
Power Outage
Disasters
Start planning now!
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9. Introduction to Failover Clustering
Introduction to Clustering
What is cluster
Why use cluster
Cluster common terminology
What is High Availability
Hardware / Software Requirements
Cluster Validations / Cluster Creations.
Introduction to WNLB
Overview of Network Load Balancing Clusters
Configuring a Network Load Balancing Cluster
Maintaining a Network Load Balancing Cluster
9

10. Failover Clustering
2+ machines (nodes)
Redundancy everywhere
Storage, NICs, HBAs, MPIO, etc.
“Shared” storage accessible by all nodes
1 node will host a HA application
Application writes data to storage
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11. Failover Clustering
Nodes monitor health of other nodes
If that node fails, health monitoring will
cause a “failover” of the resource
Another node starts the application and
reads the last saved information from the
storage
Clients experience a slight interruption in
service
11

12. What is a Failover Cluster?
Public
HA Roles
Shared
Storage
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13. Terminology Changes
Beta 1997 2000 2003 2008 R2
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14. Software Requirements
Clustering comes as an in-box feature on:
Windows Server 2008 & R2 Datacenter
Windows Server 2008 & R2 Enterprise
Windows Server 2008 & R2 for IA-64
Microsoft Hyper-V Server 2008 R2
Windows Unified Data Storage Server Enterprise
Architecture:
x64: up to 16 nodes
x86: up to 8 nodes
IA64: up to 8 nodes
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15. Building Your Cluster
2 or more computers (nodes)
2 NICs + dedicated storage adapter
3rd NIC for iSCSI
HBA
3 Networks
Public
Private (heartbeat)
HA Roles
Storage / iSCSI
Shared Storage
OS, Service or Application
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16. Mix And Match Hardware
You can use any hardware configuration if
It passes Validate
Each component has a “Certified for Windows Server 2008”
logo
Servers, Storage, HBAs, MPIO, DSMs, etc…
It’s that simple!
Connect your Windows Server 2008 logo’d hardware
Pass every test in Validate
It is now supported!
If you make a change, just re-run Validate
Details: http://go.microsoft.com/fwlink/?LinkID=119949
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17. Clustering Storage
Windows Server 2008/R2 Supported
Shared Bus Types:
Fibre Channel iSCSI SAS
• SCSI-3 SPC-3 compliant SCSI Commands
• Persistent Reservations (PRs)
• Parallel-SCSI deprecated in 2008
• Multipath IO (MPIO) recommended
• Basic GPT and MBR disks supported
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18. Networking
Key clustering component
Public network – clients
Private network – cluster communication
Storage network – nodes access “shared” storage
Multiple networks for added redundancy
Integrated with new TCP/IP Stack
Full IPv6 Support
DHCP Support for IPv4 and IPv6 Resources
Nodes can reside in different subnets
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19. Introduction to Failover Clustering
Introduction to Clustering
What is cluster
Why use cluster
Cluster common terminology
What is High Availability
Hardware / Software Requirements
Cluster Validations / Cluster Creations.
Introduction to WNLB
Overview of Network Load Balancing Clusters
Configuring a Network Load Balancing Cluster
Maintaining a Network Load Balancing Cluster
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20. Validating a Cluster
For Microsoft support, cluster must pass the built-in
Validate a Cluster Configuration (Validate) test
Run during configuration and/or after deployment
Best practices analyzed if run on configured cluster
Series of end-to-end tests on all cluster components
Configuration info for support and documentation
Networking issues
Troubleshoot in-production clusters
More information
http://go.microsoft.com/fwlink/?LinkID=119949
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21. Validate Inventories
OS Binary • Same OS version which supports clustering
• Same Hotfix and Service Pack level
Consistency
• CPU architecture
Architecture • Memory information
• Domain membership and role
Configuration • Analysis of unsigned drivers
• PnP device inventory
Devices • HBAs and NICs
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22. Validate Verifies
• Inter-node communication
Infrastructure • SCSI compatibility with Persistent Reservations
• Multiple NIC’s per server
Hardware • Shared disks accessible from all machines and
uniquely identifiable
• Each NIC has different IP address on a dissimilar
Software subnet
• Network and Disk I/O latencies
Functionality • Failover simulation
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24. WS03 – Cluster Creation
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25. WS08 & R2 – Cluster Creation
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27. Windows Network Load Balancing
(WNLB)
Overview of Network Load Balancing Clusters
Configuring a Network Load Balancing Cluster
Maintaining a Network Load Balancing Cluster
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28. What Is Network Load Balancing (NLB)?
NLB:
• Enables high availability and scalability for Internet
server-based applications
• Enables clients to access two or more servers using a single
IP address
• Requires all servers in the NLB cluster to be running the
same server applications with the same configuration
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29. How NLB Works
When using NLB:
• All servers in an NLB cluster are accessible by using a single
(virtual) IP address
• Client requests are distributed across available servers in
the NLB cluster based on a common algorithm
• All servers monitor each other through heartbeat messages
• If a server fails to send heartbeat messages for 5 seconds,
the other servers automatically converge and redistribute
the client connections across the available servers
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30. How Network Load Balancing
Clusters Work NLB Web server cluster
NLB host +
IIS server
LAN (Ethernet)
NLB host +
IIS server
Clients
NLB host +
IIS server
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31. Using Failover Clusters with
Network Load Balancing
Clients
Failover cluster
database server
NLB
Web servers
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32. Microsoft® Windows Server® 2008
NLB Features
• Network connectivity with support for:
- IPv6
- Network Driver Interface Specification (NDIS) 6.0
- Multiple dedicated IP addresses per node
• Support for up to 32 computers per cluster
• Denial of service attack and timer starvation protection
• Support for rolling upgrades from Windows Server 2003
• Network Load Balancing Manager
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33. NLB Deployment Requirements
To deploy network load balancing:
 Configure one or more network cards on all servers in
the cluster
 Configure DNS to resolve the shared IP address
 Install and configure the same applications on all
hosts in the cluster
 Deploy servers with similar hardware or plan for
variations in load balancing
 Install the Network Load Balancing feature
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35. Considerations for Configuring NLB
Clusters and Hosts
When configuring an NLB cluster, you should consider
whether:
• Each server will host the same number of client connections
• The client will connect to the same server for all connections
• The cluster will operate the same way for all applications
• Your network switches support unicast or multicast operations
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36. Comparing Unicast and Multicast
NLB Cluster Operation Modes
The cluster operation mode is used to ensure that all cluster hosts receive all
incoming client requests sent to the virtual IP address assigned to the cluster
Method Description
• All cluster hosts share an identical unicast media access control
(MAC) address
Unicast • The outgoing MAC address is modified, based on the cluster host’s
priority setting, to prevent switches from discovering that all cluster
hosts have the same MAC address
• Each cluster host retains the original adapter MAC address
Multicast • The adapter is assigned a multicast MAC address, which is shared by
all cluster hosts

37. Options for Configuring Host
Parameters
Parameter Description
Priority • Specifies a unique ID for each host
• Used to assign one server to handle all network
traffic not covered by a port rule
IP address • Must be unique in the cluster
Subnet mask • Must be the same for all hosts
Initial host state • Specifies whether NLB will start and whether the
host will immediately join the cluster

38. What Are Port Rules?
Port rules are policies that define how to direct client requests to cluster hosts
A default port rule applies to all protocols
Port rules define:
• The cluster IP address where the port rule is applied
• Port range and protocol (TCP, UDP, or both)
• Filtering for multiple hosts with affinity or single host
• Load weight
• The option to disable a port range
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39. What Is Affinity?
Affinity is a configuration option that you use to distribute
incoming client connections
Affinity options include:
• None: Allows multiple connections from the same client IP
address to be handled by different cluster hosts
• Single: Specifies that NLB direct multiple requests from
the same client IP address to the same cluster host
• Network: Specifies that NLB directs multiple requests from
the same IPv4 Class C or IPv6 network address range to
the same cluster host
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40. Resources
Cluster Team Blog: http://blogs.msdn.com/clustering/
Cluster Information Portal:
http://www.microsoft.com/windowsserver2008/en/us/clustering-home.aspx
Clustering Technical Resources:
http://www.microsoft.com/windowsserver2008/en/us/clustering-resources.aspx
Clustering Forum (2008): http://forums.technet.microsoft.com/en-
US/winserverClustering/threads/
Clustering Forum (2008 R2): http://social.technet.microsoft.com/Forums/en-
US/windowsserver2008r2highavailability/threads/
Clustering Newsgroup:
https://www.microsoft.com/technet/community/newsgroups/dgbrowser/en-
us/default.mspx?dg=microsoft.public.windows.server.clustering
Failover Clustering Deployment Guide: http://technet.microsoft.com/en-
us/library/dd197477.aspx
TechNet: Configure a Service or Application for High Availability:
http://technet.microsoft.com/en-us/library/cc732478.aspx
TechNet: Installing a Failover Cluster: http://technet.microsoft.com/en-
us/library/cc772178.aspx
TechNet: Creating a Failover Cluster: http://technet.microsoft.com/en-
us/library/cc755009.aspx
Webcast: TechNet Webcast: Build High-Availability Infrastructures with Windows Server
2008 Failover Clustering
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43. http://tinyurl.com/STEP140