always on

External Article

Adding SQL Server AlwaysOn to existing Failover Clusters

  • Article

We have a SQL Failover Cluster Instance in our primary data center, and want to implement a second two node Failover Cluster Instance in our secondary data center. A new two node cluster located in our secondary data center was setup, but I could not create a new High Availability Group between the two failover cluster instances. What went wrong?

2014-03-07

3,721 reads

External Article

AlwaysOn Architecture Guide: Building a High Availability and Disaster Recovery Solution by Using AlwaysOn Availability Groups

  • Article

SQL Server 2012 AlwaysOn Availability Groups provides a unified high availability and disaster recovery (HADR) solution that improves upon legacy functionality previously found across disparate features. Prior to SQL Server 2012, several customers used database mirroring to provide local high availability within a data center, and log shipping for disaster recovery across a remote data center. With SQL Server 2012, this common design pattern can be replaced with an architecture that uses availability groups for both high availability and disaster recovery. This paper details the key topology requirements of this specific design pattern, including quorum configuration considerations, steps required to build the environment, and a workflow that shows how to handle a disaster recovery event in the new topology.

2012-08-31

2,399 reads

External Article

A first look at SQL Server 2012 Availability Group Wait Statistics

  • Article

If you are trouble-shooting an AlwaysOn Availability Group topology, a study of the wait statistics will give a pointer to many of the causes of problems. Although several wait types are documented, there is nothing like practical experiment to familiarize yourself with new wait stats, and Joe Sack demonstrates a way of testing the sort of waits generated by an availability group under various circumstances.

2012-06-12

2,331 reads

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Question of the Day

The Internals of Writing a Page

In SQL Server, when the buffer manager write pages to disk, page protection is added to the pages. There are two types of protection: torn page protection and checksum page protection. What happens with regards to concurrency with page protection during writes?

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