| title | High Availability Solutions (SQL Server) | Microsoft Docs | |||||
|---|---|---|---|---|---|---|
| ms.custom | ||||||
| ms.date | 05/19/2016 | |||||
| ms.prod | sql-non-specified | |||||
| ms.prod_service | database-engine | |||||
| ms.service | ||||||
| ms.component | failover-clusters | |||||
| ms.reviewer | ||||||
| ms.suite | sql | |||||
| ms.technology |
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| ms.tgt_pltfrm | ||||||
| ms.topic | article | |||||
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| ms.assetid | b2eda634-0f8e-4703-801b-7ba895544ff5 | |||||
| caps.latest.revision | 84 | |||||
| author | MikeRayMSFT | |||||
| ms.author | mikeray | |||||
| manager | jhubbard | |||||
| ms.workload | Active |
[!INCLUDEappliesto-ss-xxxx-xxxx-xxx-md] This topic introduces several [!INCLUDEssNoVersion] high-availability solutions that improve the availability of servers or databases. A high-availability solution masks the effects of a hardware or software failure and maintains the availability of applications so that the perceived downtime for users is minimized.
Note! Want to know which [!INCLUDEssNoVersion] editions support a given high availability solution? See the "High Availability (Always On)" section of Features Supported by the Editions of SQL Server 2016.
[!INCLUDEssNoVersion] provides several options for creating high availability for a server or database. The high-availability options include the following:
- Always On Failover Cluster Instances
As part of the [!INCLUDEssNoVersion] Always On offering, Always On Failover Cluster Instances leverages Windows Server Failover Clustering (WSFC) functionality to provide local high availability through redundancy at the server-instance level—a failover cluster instance (FCI). An FCI is a single instance of [!INCLUDEssNoVersion] that is installed across Windows Server Failover Clustering (WSFC) nodes and, possibly, across multiple subnets. On the network, an FCI appears to be an instance of [!INCLUDEssNoVersion] running on a single computer, but the FCI provides failover from one WSFC node to another if the current node becomes unavailable.
For more information, see Always On Failover Cluster Instances (SQL Server).
- [!INCLUDEssHADR]
[!INCLUDEssHADR] is an enterprise-level high-availability and disaster recovery solution introduced in [!INCLUDEssSQL11] to enable you to maximize availability for one or more user databases. [!INCLUDEssHADR] requires that the [!INCLUDEssNoVersion] instances reside on Windows Server Failover Clustering (WSFC) nodes. For more information, see Always On Availability Groups (SQL Server).
Note! An FCI can leverage [!INCLUDEssHADR] to provide remote disaster recovery at the database level. For more information, see Failover Clustering and Always On Availability Groups (SQL Server).
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Database mirroring. Note! [!INCLUDEssNoteDepFutureAvoid] We recommend that you use [!INCLUDEssHADR] instead.
Database mirroring is a solution to increase database availability by supporting almost instantaneous failover. Database mirroring can be used to maintain a single standby database, or mirror database, for a corresponding production database that is referred to as the principal database. For more information, see Database Mirroring (SQL Server). -
Log shipping
Like [!INCLUDEssHADR] and database mirroring, log shipping operates at the database level. You can use log shipping to maintain one or more warm standby databases (referred to as secondary databases) for a single production database that is referred to as the primary database. For more information about log shipping, see About Log Shipping (SQL Server).
Our recommendation for providing data protection for your [!INCLUDEssNoVersion] environment:
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For data protection through a third-party shared disk solution (a SAN), we recommend that you use Always On Failover Cluster Instances.
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For data protection through [!INCLUDEssNoVersion], we recommend that you use [!INCLUDEssHADR].
We recommend using log shipping if you are running an edition of [!INCLUDEssNoVersion] that does not support [!INCLUDEssHADR]. For information about which editions of [!INCLUDEssNoVersion] support [!INCLUDEssHADR], see the "High Availability (Always On)" section of Features Supported by the Editions of SQL Server 2016.
Windows Server Failover Clustering (WSFC) with SQL Server
Database Mirroring: Interoperability and Coexistence (SQL Server)
Deprecated Database Engine Features in SQL Server 2016