AlwaysOn Client Connectivity (SQL Server)

This topic describes considerations for client connectivity to AlwaysOn Availability Groups, including prerequisites, restrictions, and recommendations for client configurations and settings.

In this Topic:

  • Client Connectivity Support

  • Related Tasks

Client Connectivity Support

The section below provides information about AlwaysOn Availability Groups support for client connectivity.

Driver Support

The following table summarizes driver support for AlwaysOn Availability Groups:

Driver

Multi-Subnet Failover

Application Intent

Read-Only Routing

Multi-Subnet Failover: Faster Single Subnet Endpoint Failover

Multi-Subnet Failover: Named Instance Resolution For SQL Clustered Instances

SQL Native Client 11.0 ODBC

Yes

Yes

Yes

Yes

Yes

SQL Native Client 11.0 OLEDB

No

Yes

Yes

No

No

ADO.NET with .NET Framework 4.0 with connectivity patch*

Yes

Yes

Yes

Yes

Yes

ADO.NET with .NET Framework 3.5 SP1 with connectivity patch **

Yes

Yes

Yes

Yes

Yes

Microsoft JDBC driver 4.0 for SQL Server

Yes

Yes

Yes

Yes

Yes

* Download the connectivity patch for ADO .NET with .NET Framework 4.0: http://support.microsoft.com/kb/2600211.

** Download the connectivity patch for ADO.NET with .NET Framework 3.5 SP1: http://support.microsoft.com/kb/2654347.

Important

To connect to an availability group listener, a client must use a TCP connection string.

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See Also

Concepts

Overview of AlwaysOn Availability Groups (SQL Server)

Failover Clustering and AlwaysOn Availability Groups (SQL Server)

Prerequisites, Restrictions, and Recommendations for AlwaysOn Availability Groups (SQL Server)

Availability Group Listeners, Client Connectivity, and Application Failover (SQL Server)

About Client Connection Access to Availability Replicas (SQL Server)

Other Resources

Microsoft SQL Server AlwaysOn Solutions Guide for High Availability and Disaster Recovery

SQL Server AlwaysOn Team Blog: The official SQL Server AlwaysOn Team Blog

A long time delay occurs when you reconnect an IPSec connection from a computer that is running Windows Server 2003, Windows Vista, Windows Server 2008, Windows 7, or Windows Server 2008 R2

The Cluster service takes about 30 seconds to fail over IPv6 IP addresses in Windows Server 2008 R2

Slow failover operation if no router exists between the cluster and an application server