SQL Server 2005 High availability log Shipping

SQL Server 2005, compared to SQL Server 2000来, says that there is a considerable improvement in performance and functionality, even the "revolution" to describe the upgrade. SQL Server 2005 makes SQL Server the top tier of enterprise databases. For data high availability, SQL Server 2005 provides users with data mirroring, replication, failover clustering, and log shipping capabilities. This article gives readers a brief introduction to SQL Server 2005 log shipping capabilities.

Introduction of log Shipping

Log shipping typically consists of a primary server, a secondary server, and a monitoring server (see Figure 1). The primary server is typically the server where the production database is stored, and the secondary server is used to store a copy of the production database on the primary server, and the monitoring server is optional for all detail servers used to log shipping. Log shipping is the transaction log of the primary server's production database replicated to the secondary server and restored at the secondary server to achieve consistency between the primary server production database and the secondary server database replica data.

Figure 1

Log shipping requires the primary server production database log recovery mode to be full or bulk-logged, and switching the database to the simple recovery model causes log shipping to stop working. The secondary server is the server that is used to save the most recent backup of the primary database. A secondary server can contain backup copies of databases from multiple different primary servers. For example, a department might have five servers, and each server would run a critical database system. In this case, you can use only one secondary server without having to use five separate secondary servers. Backups on five primary systems can be loaded into the backup system, reducing the amount of resources required and saving money. The monitoring server should be independent of the primary and secondary servers to avoid loss of critical information and interruption of monitoring due to loss of primary or secondary servers. A single monitoring server can monitor multiple log shipping configurations. In this case, all log shipping configurations that use the monitor server will share an alert job.