Automatic failover configuration with lightweight observer
    1.
    发明授权
    Automatic failover configuration with lightweight observer 有权
    自动故障转移配置与轻量级观察者

    公开(公告)号:US08630985B2

    公开(公告)日:2014-01-14

    申请号:US13592152

    申请日:2012-08-22

    IPC分类号: G06F17/00

    摘要: Techniques used in an automatic failover configuration having a primary database system, a standby database system, and an observer for preventing divergence among the primary and standby database systems while increasing the availability of the primary database system. In the automatic failover configuration, the primary database system remains available even in the absence of both the standby and the observer as long as the standby and the observer become absent sequentially. The failover configuration further permits automatic failover only when the observer is present and the standby and the primary are synchronized and inhibits state changes during failover. The database systems and the observer have copies of failover configuration state and the techniques include techniques for propagating the most recent version of the state among the databases and the observer and techniques for using carefully-ordered writes to ensure that state changes are propagated in a fashion which prevents divergence.

    摘要翻译: 在具有主数据库系统,备用数据库系统和观察者的自动故障转移配置中使用的技术,用于防止主数据库系统和备用数据库系统之间的分歧,同时增加主数据库系统的可用性。 在自动故障切换配置中,只要备用和观察器顺序不存在,主数据库系统即使没有备用和观察器也保持可用。 故障转移配置进一步允许自动故障转移只有当观察者存在并且备用和主要同步并且在故障切换期间禁止状态更改。 数据库系统和观察者具有故障切换配置状态的副本,并且技术包括用于在数据库和观察者之间传播最新版本的状态的技术以及使用仔细排序的写入的技术,以确保状态改变以一种方式传播 防止发散。

    Database system configured for automatic failover with user-limited data loss
    2.
    发明授权
    Database system configured for automatic failover with user-limited data loss 有权
    数据库系统配置为自动故障切换,具有用户限制的数据丢失

    公开(公告)号:US08423515B2

    公开(公告)日:2013-04-16

    申请号:US13018328

    申请日:2011-01-31

    IPC分类号: G06F17/00 G06F7/00

    摘要: Techniques used in an automatic failover configuration having a primary database system, a standby database system, and an observer. In the automatic failover configuration, the primary database system remains available even in the absence of both the standby and the observer as long as the standby and the observer become absent sequentially. The failover configuration may use asynchronous transfer modes to transfer redo to the standby and permits automatic failover only when the observer is present and the failover will not result in data loss due to the asynchronous transfer mode beyond a specified maximum. The database systems and the observer have copies of failover configuration state and the techniques include techniques for propagating the most recent version of the state among the databases and the observer and techniques for using carefully-ordered writes to ensure that state changes are propagated in a fashion which prevents divergence.

    摘要翻译: 在具有主数据库系统,备用数据库系统和观察者的自动故障转移配置中使用的技术。 在自动故障切换配置中,只要备用和观察器顺序不存在,主数据库系统即使没有备用和观察器也保持可用。 故障转移配置可能会使用异步传输模式将重做传输到备用数据库,并且只有当观察者存在时才允许自动故障转移,并且由于超出指定最大值的异步传输模式,故障转移不会导致数据丢失。 数据库系统和观察者具有故障切换配置状态的副本,并且技术包括用于在数据库和观察者之间传播最新版本的状态的技术以及使用仔细排序的写入的技术,以确保状态改变以一种方式传播 防止发散。