Lý tưởng nhất, các máy chủ chính và máy chủ ấm chờ phải ở trong vị trí khác nhau để cho một thảm họa ở một vị trí không ảnh hưởng đến người khác. Ngoài ra, bản ghi có thể đặt một nhu cầu lớn trên mạng một vài phút trong khi giao dịch các bản ghi đang được di chuyển. | Part VI Enterprise Data Management The switch between primary and warm standby server is not transparent. A series of steps must be manually executed by the DBA on the warm standby server and front-end application connections must redirect the data source and reconnect to the warm standby server. Once the primary server is repaired returning to the original configuration may require manual DBA intervention. If these issues are acceptable log shipping to a warm standby server can be an excellent safeguard against downtime. Best Practice Ideally the primary server and the warm standby server should be in different locations so that a disaster in one location will not affect the other. In addition log shipping can place a large demand on a network every few minutes while the transaction logs are being moved. If the two servers can be connected with a private high-speed network log shipping can take place without affecting other network users and the bandwidth they require. Defining Log Shipping In SQL Server 2000 log shipping was available only in Developer and Enterprise Editions. Starting with SQL Server 2005 log shipping is available in Workgroup Standard Developer and Enterprise Editions. Developer Edition can be used only for development purposes and not for production. Microsoft provides a simple-to-use log shipping wizard to create a maintenance plan to back up copy and restore the transaction log from the primary server to the warm standby server every few minutes. Log shipping has built-in monitoring that makes it very easy to maintain and troubleshoot. Log shipping normally involves three SQL Servers a primary server a warm standby server and a monitor server as shown in Figure 46-1. The primary or source server is the main production SQL Server to which clients connect. This server contains the log shipping database. The initial full database backup and subsequent transaction log backups are taken on this server. This server should be a high-quality server
