Design for Business Continuity and Data Availability
These questions are based on 70-647: PRO: Windows Server 2008, Enterprise Administrator
Self Test Software Practice Test
Objective: Design for business continuity and data availability.
Sub-objective: Design for data management and data access.
Single answer, multiple-choice
You are the administrator for a company that hosts a Web site used for customers to order products and view merchandise. All servers are running Windows Server 2008. Due to increased workload, you plan to implement a second server to house the same Web site. Which of the following redundancy methods would eliminate a single point of failure and provide the users with the most transparent failover in the case of a server failure?
- Use round-robin DNS (RRDNS).
- Install a single-load balancing switch.
- Use Network Load Balancing.
- Install redundant network cards.
C. Use Network Load Balancing.
Network Load Balancing (NLB) would eliminate a single point of failure and provide the users with the most transparent failover in the case of a server failure. NLB is a component in the Windows Server 2008 operating system that balances the workload among multiple servers in an NLB cluster. It provides smooth and automatic failover for a user when the node being utilized fails.
Round-robin DNS (RRDNS) also can be used to balance the workload between servers hosting the same site. However, failover is less than smooth for the user and usually requires refreshing the browser. It involves creating DNS records that map the site name to multiple addresses and then manually configuring distribution of the workload.
Load-balancing switches are another way to balance workload at the MAC address level. The switches are quite expensive, and a single one would itself be a single point of failure.
Installing redundant network cards would provide neither load balancing nor redundancy. It would only allow a single machine to continue to accept work if one of cards stopped working and could improve the performance.