Transcript Example Title with Registration Microsoft® and Trademark SQL

Module 13: Network Load
Balancing Fundamentals
Module 13: Network Load Balancing Fundamentals
• Server Availability and Scalability Overview
• Windows Network Load Balancing
• Configuring Windows Network Load Balancing
Lesson 1: Server Availability and Scalability Overview
• What Is Availability?
• What Is Scalability?
• What Is Load Balancing?
• Comparing Hardware and Software Load Balancing
• What Is Failover Clustering?
What Is Availability?
Availability is a level of service that
applications, services, or systems provide,
expressed as a percentage of time
Highly available services or systems are
available more than 99% of the time
High availability:
• Requirements differ based on how availability is
measured
• Does not typically include planned outages when
calculating availability
What Is Scalability?
Scalability measures the ability to increase capacity
Scaling up:
• Increases the capacity of a single server
• Involves adding more or better hardware to a server
Scaling out:
• Increases the capacity of an application
• Involves adding additional servers to perform
processing
What Is Load Balancing?
Load Balancing is a system that
increases the scalability and
availability of the servers that
provide access to data
Other load balancing methods:
• A virtual IP address is used to distribute requests
between multiple servers
• Not suitable for all applications
Comparing Hardware and Software Load Balancing
Hardware load balancing:
• Uses a device to provide the virtual IP
• Requires multiple devices to guarantee fault tolerance
Software load balancing:
• All cluster nodes provide the virtual IP
• There is no single point of failure
What Is Failover Clustering?
Private
Network
Active Node
Shared
Storage
Public
Network
Active Node
Passive Node
Lesson 2: Windows Network Load Balancing
• What Is Windows Network Load Balancing?
• Requirements for Windows Network Load Balancing
• How Windows Network Load Balancing Works
• Data Synchronization between NLB Nodes
What Is Windows Network Load Balancing?
Windows NLB:
• Is a fully distributed software solution for load balancing
• Is included with all versions of Windows Server® 2008
Session Broker:
• For Terminal Services
• Distributes session requests to the least loaded server
• Provides scalability and availability
• Included in all version of Windows Server 2008
Requirements for Windows Network Load Balancing
Requirements:
• At least one network adapter for load balancing
• Only TCP/IP on the NLB adapter
• All NLB nodes on the same subnet
How Windows Network Load Balancing Works
Unicast mode:
• A unique NLB MAC address is assigned to NLB adapter in all
nodes
• The original MAC address of the NLB adapter cannot be used
• Packets are received by all NLB nodes
• Only the appropriate NLB node responds
• Outgoing MAC is unique for each node to avoid switch problems
Multicast mode:
• A multicast MAC address is assigned to the NLB adapter in all
nodes
• The original MAC address of the NLB adapter can still be used
• Removes the need for two network adapters
• Only the appropriate NLB node responds
Data Synchronization between NLB Nodes
All NLB nodes must have the same data to make sure
that all nodes respond identically to requests
Data access can be provided by:
• Synchronizing content between servers
• Storing data in a common location
Database Server
NLB Cluster
Lesson 3: Configuring Windows Network Load
Balancing
• What Are the Cluster Parameters?
• What Are Port Rules?
• What Is the Filtering Mode?
• What Is Affinity?
• What Are the Host Parameters?
• Demonstration: Creating an NLB Cluster
What Are the Cluster Parameters?
Cluster parameters include the following:
Cluster parameter
Description
IP address
Virtual IP address of the NLB cluster
Network address
MAC address of the NLB cluster
Cluster operation mode
Specified whether unicast or multicast
operation is used
What Are Port Rules?
Port rules specify how requests to a certain IP address
and port range are handled
Port rules define:
• Filtering mode
• Affinity
• Load weight
• Handling priority
What Is the Filtering Mode?
Filtering mode
Multiple hosts
Single host
Disable this port range
Description
All NLB nodes respond based on the weight
assigned to each node
Only the NLB node with the highest priority
responds
All traffic for this port range is blocked
What Is Affinity?
Affinity controls how requests from a client are
distributed among multiple nodes in an NLB cluster
Affinity
None
Single
Network
Description
Each client request could be distributed to any
node
All requests from a single client are distributed to
a single node
All requests from a single class C sized network
are distributed to a single node
What Are the Host Parameters?
Host parameters include the following:
Host parameter
Initial host state
Dedicated IP address
Priority
Description
Specifies whether the host automatically
joins the NLB cluster when started
IP address that is used on the host for
cluster management
Determines in which order the host is when
a port rule does not apply
Demonstration: Creating an NLB Cluster
In this demonstration, you will see how to configure an NLB
cluster
Lab: Implementing Network Load Balancing
• Exercise 1: Preparing Web Servers for NLB
• Exercise 2: Creating an NLB Cluster for Failover
• Exercise 3: Configuring an NLB Cluster for Load Balancing
Logon information
Virtual machine
NYC-DC1, NYC-WEB,
NYC-SVR1
User name
Administrator
Password
Pa$$w0rd
Estimated time: 60 minutes
Lab Review
• When an NLB cluster is configured with single host filtering
mode, how is the responding node determined?
• When an NLB cluster is configured with multihost filtering
mode, how is the responding node determined?
Module Review and Takeaways
• Review Questions
• Real-world Issues and Scenarios
• Best Practices
• Tools