Thursday, June 23, 2011

Windows Server 2008 R2 System-Level Fault Tolerance (Clustering/Network Load Balancing)

Many businesses today rely heavily on their computer and network infrastructure. Internet access, email, instant messaging, file and print services, and networking services such as domain name system (DNS), Dynamic Host Configuration Protocol (DHCP), and virtual private networking are just a few of the core computer and networking services that are critical to many businesses. If one of these critical systems is down or unexpectedly offline, the impact to the business can be huge. When businesses cannot withstand extended periods of unexpected or unplanned downtime, deploying a fault-tolerant computer and network infrastructure might be necessary.

Windows Server 2008 R2 provides several methods of improving system- and service-level fault-tolerance by leveraging some of the roles, role services, and features included in the different editions of the operating system. The Distributed File System (DFS) can be used to create and deploy redundant and automatically synchronized file data through DFS shares and DFS Replication. Another example of providing redundant services is to design an infrastructure that includes multiple domain controllers and print services in each major site and for remote sites, configuring the Active Directory site properties to utilize remote site domain controllers when local services become unavailable.

Windows Server 2008 R2 provides many functions and services that can extend and enhance the reliability and resilience of computer and networking services. Many services, however, are only available when deployed on specific hardware platforms and when deployed on the Enterprise or Datacenter Editions of Windows Server 2008 R2. This chapter covers system level fault tolerance using Windows Server 2008 R2 Network Load Balancing (NLB) and failover clusters. NLB is available in Standard, Enterprise, and Datacenter Editions of Windows Server 2008 R2. Failover clusters are available only in the Enterprise and Datacenter Editions of Windows Server 2008 R2. These built-in clustering technologies provide load-balancing and failover capabilities that can be used to increase fault tolerance for many different types of applications and network services. Each of these clustering technologies is different in many ways. Choosing the right Windows Server 2008 R2 clustering technology depends on the services and applications that will be hosted by the cluster.

Windows Server 2008 R2 technologies such as NLB and failover clusters improve fault tolerance for services, but before these clustering technologies can be leveraged effectively, basic server or system stability best practices must be used.

Source of Information : Sams - Windows Server 2008 R2 Unleashed (2010)

No comments: