You work as the database administrator at Domain.com. The Domain.com network consists of a single Active Directory domain named Domain.com. All servers on the Domain.com network run Windows Server2003. The Domain.com network contains two SQL Server 2005 database servers named Certkiller -DB01 and Certkiller -DB02, and a member server named Certkiller -SR33. A database mirroring session operating in synchronous mode is in operation between Certkiller -DB01 and Certkiller -DB02, with Certkiller -DB01 being the principal database server. Certkiller -DB01 hosts a database named CK_Sales that stores sales data from Domain.com’s e-Commerce Web site. One Monday morning you discover that the CK_Sales database is unavailable. You discover that Certkiller -DB01 is offline while Certkiller -DB02 is online; however, failover to Certkiller -BD02 did not occur. This failure has adversely affected the profitability of Domain.com’s e-Commerce division. You need to improve the availability of the CK_Sales database. You are unable to acquire any additional hardware.
What should you do?
A.
Configure Certkiller -DB01 and CERTKILLER-DB02 in a failover cluster with two active nodes.
B.
Configure the mirrored database session to run in asynchronous mode.
C.
Install SQL Server 2005 on Certkiller -SR33 and configure it as a witness server.
D.
Configure the mirrored database to operate in high-safety mode.
Explanation:
High-safety mode supports synchronous operation in which all transactions must be committed to both partners. This provides zero-loss of data but requires a witness to provide automatic failover.
Incorrect Answers:
A: Failover clustering would require additional hardware in the form of a shared external hard disk drive. You, however, are unable to acquire additional hardware. Database mirroring is a software solution, but requires a witness server to provide failover.
B: In Asynchronous mode a transaction is committed to the principal database without requiring the principal database to wait for the mirror database to write the transaction log to disk. This maximizes performance for the mirrored database but at the expense of high-availability. When the principal server of a mirrored database in asynchronous operation fails, you must manually stop the mirror session, update the database and begin a new mirroring session.
D: High-safety mode supports synchronous operation in which all transactions must be committed to both partners. This provides zero-loss of data but requires a witness to provide automatic failover.
Reference:
Microsoft SQL Server 2005 Books Online (2006), Index: database mirroring [SQL Server], about database mirroring
Microsoft SQL Server 2005 Books Online (2006), Index: database mirroring [SQL Server], asynchronous
Microsoft SQL Server 2005 Books Online (2006), Index: database mirroring [SQL Server], synchronous