High Availability

Microsoft SQL Server 2012 Always On AGs at StackOverflow

I recently finished helping the StackExchange team migrate their SQL Server 2008 infrastructure to SQL Server 2012. These servers power StackOverflow, DBA.StackExchange.com, the new AskPatents partnership with the US Patent and Trademark Office, and hundreds of other Q&A sites that together form one of the biggest web site networks. It’s one of the most visible…
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Why Your SQL Server’s Network Connection Matters

If you’re using SQL Server 2012’s hot new AlwaysOn Availability Groups feature, your databases will go offline when your network connection does – even if you’re using asynchronous replication. This is not a bug.  This is working as designed – and it’s important to understand the underlying concepts. Nothing to see here, I'm just going…
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SQL Server Always On Availability Groups in AWS

Many companies are investigating a move into cloud hosting. With the recent release of SQL Server 2012, these very same companies are also looking at a migration to SQL Server 2012 to take advantage of readable secondaries. Combining Amazon Web Services and SQL Server 2012 seems like a perfect match. Unfortunately, there are some gotchas,…
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Where to Run DBCC on Always On Availability Groups

With SQL Server 2012’s new AlwaysOn Availability Groups, we have the ability to run queries, backups, and even DBCCs on database replicas.  But should we? Paul Randal (Blog – @PaulRandal) covered this issue in today’s SQLskills Insider newsletter, and he says: “It’s not checking the I/O subsystem of the log shipping primary database – only…
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How to Set Up SQL Server 2012 Always On Availability Groups

Before we get started, we need to talk about something. I’m going to be using the C word – that’s right, Clustering. Deep, calming breaths. Relax. We can do this, you and me. This isn’t the old-school clustering with shared disks, heartbeat networks, and hardware compatibility lists. This is just another feature you’re going to…
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Fairly Safe

SQL Server 2012 AlwaysOn Availability Groups Rock

SQL Server 2012 brings huge improvements for scaling out and high availability. To put these changes into perspective, let’s take a trip down memory road first and look at the history of database mirroring. SQL Server 2005 first introduced mirroring, although it wasn’t fully supported until a service pack. In many ways, mirroring beat the…
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Mirrors aren’t backups

Are you using any of these technologies as a method of database protection? Database mirroring (keeping two database servers synchronized with the same data via SQL 2005/2008) Replication (copying records between databases) Log shipping (copying log files to another server and restoring them immediately) SAN-based mirroring (storing two copies of your database on two different…
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