TAILIEUCHUNG - Hướng dẫn học Microsoft SQL Server 2008 part 117

Failover clustering Windows không được thiết kế để làm như sau: ■ Cung cấp các kết nối liên tục: Trong quá trình failover, bất kỳ hoạt động SQL Server kết nối khách hàng bị phá vỡ. Vì vậy, tất cả các giao dịch noncommitted cần phải được thực hiện một lần nữa, trừ khi các giao dịch được xử lý trong ứng dụng. | Part VI Enterprise Data Management Windows failover clustering is not designed to do the following Provide continuous connectivity During the failover process any active SQL Server client connections are broken. Therefore all noncommitted transactions need to be performed again unless the transactions are handled within the application. If the application is cluster-aware the failover is completely transparent. Protect data Implementing SQL Server 2008 failure clustering does not obviate the need to take backups or run consistency checks DBCC CHECKDB . Because failover clustering does not protect data it is still necessary to run backups and restore them on another server run DBCC CHECKDB etc. Protect a shared disk array from failing Failover clustering is not designed to protect against a disk failure. It is recommended to combine failover clustering with hardware redundancy such as SAN to provide data loss protection. Prevent hack attacks Prevent network failures Protect the server from other potential disasters such as power outages Provide load balancing Failover clustering is not like network load balancing. It does not provide any automatic balancing although DBAs can manually balance the load using Cluster Administrator. availability solution. Microsoft SQL Server 2008 failover clustering is part of an entire strategy needed to help reduce downtime. Having a failover cluster does not mean that you have a complete high- How SQL Server 2008 failover clustering works The clustered nodes use a heartbeat signal to check whether each node is alive at both the Windows and SQL Server levels. At the Windows level the cluster nodes are in constant communication thereby validating the health of all the nodes. After installing SQL Server 2008 failover clustering the nodes that run the SQL Server resource perform two types of checks LooksAlive Every five seconds it checks whether the SQL Server service is running. IsAlive Every 60 seconds it runs a simple Transact-SQL .

• Cơ sở dữ liệu
• Giáo trình SQL Server 2008
• Microsoft SQL Server 2008
• quản trị dữ liệu
• cài đặt SQL Server 2008
• công cụ của SQL Server 2008
• Giáo trình Microsoft SQL Server 2008
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• Cài đặt Microsoft SQL Server 2008
• Cấu trúc trình đơn của Microsoft SQL Server 2008
• Cơ sở dữ liệu SQL Server 2008
• Dịch vụ Report trong SQL Server 2008
• SQL Server Business Intelligence Development Studio
• Bảo mật cơ sở dữ liệu SQL Server 2008
• SQL Server 2008
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• Kiến trúc SQL Server 2008
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