11 server clustering chapter 6. chapter 6: server clustering2 overview list the types of server...
TRANSCRIPT
11
SERVER CLUSTERING
Chapter 6
Chapter 6: SERVER CLUSTERING 2
OVERVIEW
List the types of server clusters.
Determine which type of cluster to use for your applications.
Describe how Network Load Balancing and server clusters work.
Deploy an NLB cluster.
Deploy a server cluster.
Chapter 6: SERVER CLUSTERING 3
WINDOWS SERVER 2003 CLUSTER TYPES
Server clusters
Network Load Balancing clusters
Chapter 6: SERVER CLUSTERING 4
SERVER CLUSTERS
Chapter 6: SERVER CLUSTERING 5
NETWORK LOAD BALANCING
Chapter 6: SERVER CLUSTERING 6
DESIGNING A CLUSTERING SOLUTION
What are you protecting against? Software failure
Hardware failure
Site failure
Chapter 6: SERVER CLUSTERING 7
ESTIMATING AVAILABILITY REQUIREMENTS
Decide what applications are required, and how much downtime can be tolerated.
Consider what threats may be present—they will not be the same in every situation or environment.
Investment in fault tolerance and availability is governed by the laws of diminishing returns. Spending twice as much will not provide double the protection.
Chapter 6: SERVER CLUSTERING 8
SCALING CLUSTERS
Scale up
Improve performance of systems by installing a more powerful processor and adding RAM and higher performance disk subsystems.
Scale out
Add servers to cluster to increase overall processing power.
Chapter 6: SERVER CLUSTERING 9
HOW MANY CLUSTERS?
Chapter 6: SERVER CLUSTERING 10
COMBINING CLUSTERING TECHNOLOGIES
Chapter 6: SERVER CLUSTERING 11
DISPERSING CLUSTERS
Geographic separation provides higher availability in situations such as: Natural disaster (flood, earthquake, tornado)
Power failure, rolling blackouts
Theft, vandalism, terrorism
Chapter 6: SERVER CLUSTERING 12
USING NETWORK LOAD BALANCING
Easier to install, configure, and maintain than server clustering.
Does not require additional storage hardware.
No additional software is required.
Managed via the Network Load Balancing Manager application.
Chapter 6: SERVER CLUSTERING 13
UNDERSTANDING NETWORK LOAD BALANCING
Each NLB cluster can consist of up to 32 servers.
A virtual network adapter acts as an intermediary between the physical network interface and the protocol stack.
An algorithm associated with the virtual network adapter determines which requests should be answered and which should be ignored.
Chapter 6: SERVER CLUSTERING 14
PLANNING A NETWORK LOAD BALANCING DEPLOYMENT
Chapter 6: SERVER CLUSTERING 15
NLB OPERATIONAL MODES
Unicast mode
Servers in the cluster can only communicate with each other if more than one network interface is installed in the server.
Multicast mode
Servers with one network card can communicate with each other, but any routers on the network must support multicast MAC addresses.
Chapter 6: SERVER CLUSTERING 16
NLB NETWORKING
Servers in an NLB cluster determine independently whether or not to process an incoming request.
Servers in an NLB cluster transmit heartbeat messages to let the other servers in the cluster know they are running and operational.
Heartbeats are the only cluster-related communication between servers in an NLB cluster.
Chapter 6: SERVER CLUSTERING 17
DEPLOYING A NETWORK LOAD BALANCING CLUSTER
Chapter 6: SERVER CLUSTERING 18
MONITORING NETWORK LOAD BALANCING
Monitoring of NLB clusters can be performed using: Network Load Balancing Manager
Event Viewer
Chapter 6: SERVER CLUSTERING 19
USING NETWORK LOAD BALANCING MANAGER
Chapter 6: SERVER CLUSTERING 20
USING EVENT VIEWER
Chapter 6: SERVER CLUSTERING 21
USING NLB.EXE
Command line utility used to configure and manage NLB clusters
Enables commands to be placed into scripts and batch files
Chapter 6: SERVER CLUSTERING 22
DESIGNING A SERVER CLUSTER
Designing a server cluster deployment
Planning a server cluster hardware configuration
Creating an application deployment plan
Selecting a quorum model
Creating a server cluster
Configuring failover policies
Chapter 6: SERVER CLUSTERING 23
DESIGNING A SERVER CLUSTER DEPLOYMENT
Chapter 6: SERVER CLUSTERING 24
PLANNING A SERVER CLUSTER HARDWARE CONFIGURATION
All servers in the cluster must be running the same edition of Windows Server 2003.
All servers in the cluster must have the same processor architecture: 32-bit or 64-bit.
At least one network interface per system is required. Two are preferred.
Shared storage connection is required.
Chapter 6: SERVER CLUSTERING 25
USING SCSI
Chapter 6: SERVER CLUSTERING 26
USING FIBRE CHANNEL
Chapter 6: SERVER CLUSTERING 27
CREATING AN APPLICATION DEPLOYMENT PLAN
Single-instance applications
Applications that can run on no more than one server at a time, using a given configuration
Multiple-instance applications
Applications in which duplicated code can run on multiple nodes in a cluster or in which the code can be partitioned
Chapter 6: SERVER CLUSTERING 28
DEPLOYING SINGLE-INSTANCE APPLICATIONS
Chapter 6: SERVER CLUSTERING 29
CAPACITY PLANNING
Idle servers in a standby configuration must be capable of running the application(s) on the active server.
Depending on the failover configuration, the idle server may be required to run more than one application in the event of a multiple server failure.
Chapter 6: SERVER CLUSTERING 30
DEPLOYING MULTIPLE-INSTANCE APPLICATIONS
Chapter 6: SERVER CLUSTERING 31
SELECTING A QUORUM MODEL
Single-node cluster
Single-quorum device cluster
Majority node set cluster
Chapter 6: SERVER CLUSTERING 32
CREATING A SERVER CLUSTER
Chapter 6: SERVER CLUSTERING 33
CONFIGURING FAILOVER POLICIES
Failover pairs
Hot-standby server
N+I
Failover ring
Random
Chapter 6: SERVER CLUSTERING 34
CHAPTER SUMMARY
A cluster is a group of servers that appears to users as a single resource and that provides high availability, reliability, and scalability for specific applications.
A Network Load Balancing cluster is a group of servers running a stateless application, such as a Web server, each of which has an identical, independent data store.
A server cluster is a group of servers running a stateful application, such as a database server, and sharing a common data store.
Chapter 6: SERVER CLUSTERING 35
CHAPTER SUMMARY (continued)
Network Load Balancing works by creating a virtual network adapter with IP and MAC addresses that represent the cluster as a single unit.
When NLB is running in unicast mode, ordinary communication between cluster servers is impossible. In multicast mode, the cluster servers can communicate normally.
Although NLB and server clusters can both function with a single network interface adapter installed in each server, using multiple adapters in each server can prevent network performance degradation.
Chapter 6: SERVER CLUSTERING 36
CHAPTER SUMMARY (continued)
A server cluster requires a storage resource shared by the nodes in the cluster. Windows Server 2003 supports shared SCSI and Fibre Channel for this purpose.
In a server cluster, the quorum is a storage resource that contains cluster configuration data, which nodes use to create their configuration databases as they join the cluster.
You can configure a cluster to use various failover policies by specifying which nodes are permitted to run various cluster resources.
Chapter 6: SERVER CLUSTERING 37
CHAPTER SUMMARY (continued)
To create and manage server clusters, use the Cluster Administrator application. To manage Network Load Balancing clusters, use Network Load Balancing Manager.