MSSQL读写分离:实现高效数据访问(mssql读写分离原理)
MSSQL读写分离功能是指把MSSQL数据库中的读写操作分开,用一组读数据库服务器和一组写数据库服务器独立完成。MSSQL读写分离有助于改善数据库的性能,可以使读取和写入数据库得到有效分离,极大提升数据存取效率。
MSSQL读写分离实现主要分以下几个步骤:
1. 创建只读复制,只读复制是一组读服务器的集合,它们保持主服务器的一致性,并能够进行数据的读取操作,但不能进行写入操作。
2. 将应用程序或网站设置为只读负载均衡,让应用程序或网站可以在多个只读服务器上实现负载均衡,提高数据查询的效率。
3. 配置主服务器只接受更新请求。一般情况下,除只读复制的多个服务器,就只需要一台主服务器来接受写操作,比如插入、更新和删除操作,以减轻主服务器的负担。
4. 配置主服务器的更新参数,通过配置更新参数,可以确保更新操作在主服务器上被正确处理,而多余的更新操作不会影响主库。
实现MSSQL读写分离后,我们可以得到更强大的数据处理能力,而且能够极大提高应用程序的效率。如果需要使用读写分离,那么可以使用下面的代码实现:
–Download the Microsoft Data Access Components(MDAC)
–Create a new Read Write server
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USE [master]
GO
CREATE AVAILABILITY GROUP [ReadWriteGroup]
WITH (AUTOMATED_BACKUP_PREFERENCE = SECONDARY, HEALTH_CHECK_TIMEOUT = 30 )
FOR REPLICA ON
N’ReadWriteServer’
WITH (ENDPOINT_URL = N’TCP://ReadWriteServer:1433′, FAILOVER_MODE = MANUAL,
AVAILABILITY_MODE=SYNCHRONOUS_COMMIT, SEEDING_MODE = AUTOMATIC, BACKUP_PRIORITY = 50, SECONDARY_ROLE(ALLOW_CONNECTIONS = NO));
GO
–Create a new Read Only server
USE [master]
GO
CREATE AVAILABILITY GROUP [ReadOnlyGroup]
WITH (AUTOMATED_BACKUP_PREFERENCE = SECONDARY, HEALTH_CHECK_TIMEOUT = 30 )
FOR REPLICA ON
N’ReadOnlyServer’
WITH (ENDPOINT_URL = N’TCP://ReadOnlyServer:1433′, FAILOVER_MODE = MANUAL,
AVAILABILITY_MODE = SYNCHRONOUS_COMMIT, SEEDING_MODE = AUTOMATIC, BACKUP_PRIORITY = 50, SECONDARY_ROLE(ALLOW_CONNECTIONS = YES));
GO
–Create the Primary replica
USE master
GO
ALTER AVAILABILITY GROUP [ReadWriteGroup]
SET (PRIMARY_ROLE (READ_ONLY_ALLOWED = NO))
GO
–Create the Secondary replica
USE master
GO
ALTER AVAILABILITY GROUP [ReadOnlyGroup]
SET (PRIMARY_ROLE (READ_ONLY_ALLOWED = YES))
GO
–Synchronize the availability group
USE master
GO
ALTER AVAILABILITY GROUP [ReadWriteGroup]
JOIN
GO
ALTER AVAILABILITY GROUP [ReadOnlyGroup]
JOIN
GO
–Create the routing list
USE master
GO
ALTER AVAILABILITY GROUP [ReadWriteGroup]
ADD
REPLICA ON ‘ReadWriteServer’
WITH (AVAILABILITY_MODE = SYNCHRONOUS_COMMIT)
GO
ALTER AVAILABILITY GROUP [ReadWriteGroup]
ADD
REPLICA ON ‘ReadOnlyServer’
WITH (AVAILABILITY_MODE = ASYNCHRONOUS_COMMIT)
GO
–Create the listener
USE master
GO
CREATE AVAILABILITY GROUP LISTENER [ReadWriteListener]
WITH (
DNS_NAME = N’readwritelistener.domain.com’,
PORT = 1433,
AVAILABILITY_GROUP = N’ReadWriteGroup’
)
GO
使用上述步骤,就可以实现MSSQL读写分离,从而极大地提高数据处理的效率。