[AlwaysOn] AlwaysOn可用性組的故障轉移和故障轉移模式[中英文對照] 2

自動故障轉移

Automatic failover

在丟失主副本時自動發生的故障轉移。僅噹噹前主副本和一個輔助副本同時配置為使用自動故障轉移模式，並且輔助副本當前已同步時，才支援自動故障轉移。如果主副本或輔助副本的故障轉移模式設定為手動，則不能發生自動故障轉移。

A failover that occurs automatically on the loss of the primary replica.   Automatic failover is supported only when the current primary and one   secondary replica are both configured with failover mode set to AUTOMATIC and   the secondary replica currently synchronized. If the failover mode of either   the primary or secondary replica is MANUAL, automatic failover cannot occur.

計劃的手動故障轉移(無資料丟失)

Planned manual failover   (without data loss)

計劃的手動故障轉移或“手動故障轉移”通常是由資料庫管理員為了進行管理而啟動的故障轉移。僅當主副本和輔助副本同時配置為使用同步提交模式並且輔助副本當前已同步(處於同步狀態)時，才支援計劃的手動故障轉移。當目標輔助副本同步後，即使主副本已崩潰，也可以進行手動故障轉移(無資料丟失)，因為輔助資料庫已準備好進行故障轉移。資料庫管理員需要手動啟動手動故障轉移。

Planned manual failover, or manual failover, is a failover that   is initiated by a database administrator, typically, for administrative   purposes. A planned manual failover is supported only if both the primary   replica and secondary replica are configured for synchronous-commit mode and   the secondary replica is currently synchronized (in the SYNCHRONIZED state). When   the target secondary replica is synchronized, manual failover (without data   loss) is possible even if the primary replica has crashed because the   secondary databases are ready for failover. A database administrator manually   initiates a manual failover.

強制故障轉移(可能丟失資料)

Forced failover (with   possible data loss)

當沒有任何輔助副本與主副本同步，或者主副本未執行且沒有輔助副本準備好進行故障轉移時，可由資料庫管理員啟動的故障轉移。強制故障轉移存在資料丟失的風險，建議嚴格限制用於災難恢復。強制故障轉移也稱為強制手動故障轉移，因為它只能手動啟動。這是非同步提交可用性模式下支援的唯一故障轉移形式。

A failover that can be initiated by a database administrator when no   secondary replica is SYNCHRONIZED with the primary replica or the primary   replica is not running and no secondary replica is failover ready. Forced failover   risks possible data loss and is recommended strictly for disaster recovery.   Forced failover is also known as forced manual failover because it can only   be initiated manually. This is the only form of failover supported by in   asynchronous-commit availability mode.

自動故障轉移集

Automatic failover set

在給定的可用性組中，僅當一對可用性副本(包括當前主副本)配置為使用同步提交模式以及自動故障轉移(如果有)時，才發生這種故障轉移。僅當次要副本當前已與主要副本同步時，自動故障轉移集才會生效。

Within a given availability group, a pair of availability replicas   (including the current primary replica) that are configured for   synchronous-commit mode with automatic failover, if any. An automatic   failover set takes effect only if the secondary replica is currently   SYNCHRONIZED with the primary replica.

同步提交故障轉移集

Synchronous-commit   failover set

在給定的可用性組中，僅當一組(兩個或三個)可用性副本(包括當前主副本)配置為使用同步提交模式(如果有)時，才發生這種故障轉移。僅當輔助副本配置為使用手動故障轉移模式，並且至少一個輔助副本當前與主要副本同步時，同步提交故障轉移集才會生效。

Within a given availability group, a set of two or three availability   replicas (including the current primary replica) that are configured for   synchronous-commit mode, if any. A synchronous-commit failover settakes   effect only if the secondary replicas are configured for manual failover mode   and at least one secondary replica is currently SYNCHRONIZED with the primary   replica.

整個故障轉移集

Entire failover set

在給定的可用性組內，其執行狀態當前為聯機的所有可用性副本的集合，而不考慮可用性模式和故障轉移模式。僅在當前沒有輔助副本與主要副本同步時，整個故障轉移集才會變為相關。

Within a given availability group, the set of all availability replicas   whose operational state is currently ONLINE, regardless of availability mode   and of failover mode. The entire failover setbecomes relevant when no   secondary replica is currently SYNCHRONIZED with the primary replica.