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Category: Availability Groups

Deploying SQL Server with Availability Groups via HPE Serviceguard for LInux and Ansible

Amit Khandelwal packs a lot into a post:

It’s time for a new blog on how Ansible can simplify SQL Server deployment, configuration, and availability. If you’ve read my previous blogs on Ansible for SQL Server installation and configuration, and the pacemaker-based Always On availability group, you know how powerful Ansible can be. Now, let’s talk about HPE Serviceguard for Linux (SGLX), a high availability/disaster recovery solution that provides business continuity for critical applications like SQL Server.

Deploying SQL Server Always On availability groups on HPE SGLX is a fully supported solution for production workloads.

Today, let’s look at how you can configure Always On availability group based on HPE SGLX via Ansible. We have collaborated with our friends in HPE to enable the Ansible based deployment for HPE SGLX with SQL Server. This feature is now available for HPE SGLX 15.10. For this demonstration, you can download the evaluation bits from the ‘My HPE Software Center‘. The Ansible bits with the scripts are available on GitHub

Read on for instructions and what you need to make it all work.

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Scale-Out Read-Only Databases in Azure SQL DB

Etienne Lopes begins a new series:

As part of High Availability architecture, each single database, elastic pool database, and managed instance in the Premium and Business Critical service tier is automatically provisioned with a primary read-write replica and one or more secondary read-only replicas.”

Read on to see how you can add support for read-only, scale-out replicas to an existing Azure SQL Database. Just know how much that bill is going to be.

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File Not Found in SQL Server 2022 with Distributed AG and Filestream

Sean Gallardy goes sleuthing:

I don’t often find many people using FileStream in their databases (which isn’t a bad or good thing, in my opinion, just a statement of fact). Some technologies in SQL Server use it behind the scene, such as FileTable or Hekaton, and there isn’t really any getting around it in those cases. However, I was brought an interesting issue by a friend on Database Administrators Stack Exchange, Hannah Vernon (w), when it came to a database that was in a Distributed Availability Group in 2019 and had no issues, but after upgrading to SQL Server 2022, started having a major problem.

Read on for Sean’s analysis of the problem and solution.

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Understanding Log Send Queue, Redo Queue, and Redo Rate

Greg Dodd explains three terms:

A quick description of 3 metrics that SQL tracks in Availability Groups. These metrics are important when evaluating the health of your Availability Group, and knowing what sort of data loss you might face in a failover. Remember, just because you told SQL to make your AAG Synchronous, doesn’t mean you won’t have data loss.

Click through for the definitions.

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Identifying Rows in sp_wait_for_database_copy)_sync

Jose Manuel Jurado Diaz troubleshoots a problem:

As you could see in this public documentation Auto-failover groups overview & best practices – Azure SQL Database | Microsoft Learn about sp_wait_for_database_copy_sync “sp_wait_for_database_copy_sync prevents data loss after geo-failover for specific transactions, but does not guarantee full synchronization for read access. The delay caused by a sp_wait_for_database_copy_sync procedure call can be significant and depends on the size of the not yet transmitted transaction log on the primary at the time of the call.”

Our customer asked about several scenarios to understand this behaviour and also, verify if there is possible to identify the rows that have not been synced. For this, I developed a POC to test it:

Read on to see what you’d need to do.

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“The Function Requested Is Not Supported” Errors on Availability Groups

David Fowler troubleshoots an issue:

Checking the logs on the secondary, it was littered with ‘Database Mirroring login attempt failed with error: ‘Connection handshake failed. An OS call failed: (80090302) 0x80090302(The function requested is not supported).’ messages. The primary server wasn’t able to authenticate with the secondary, but why? Everything looked ok as far as I could see.

Click through for the fruits of David’s labor.

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Contained SQL Agent Jobs in SQL Server 2022

Allan Hirt looks at contained SQL Server Agent Jobs:

I previously wrote about Contained AGs in SQL Server 2022 and demonstrated how to create a contained login. In this blog post, I’m going to talk about contained SQL Server Agent jobs because just like logins, they are a bit confusing from an administative standpoint in their current pre-release implementation (this blog post was written using SQL Server 2022 RC0 using SSMS 19 Preview 3).

It sounds like there’s still a ways to go on the tooling side of things.

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The Ins and Outs of Contained Availability Groups

Eitan Blumin does some digging:

Notice that all of the highlighted databases and server objects belong to the contained availability group, and all other databases and objects are not visible anymore. This is because our “master” and “msdb” databases are now the contained system databases which are separate from the actual instance system databases.

For more details about contained availability groups, such as interoperability support with other SQL Server features and more, check out the official Microsoft documentation at:

https://docs.microsoft.com/sql/database-engine/availability-groups/windows/contained-availability-groups-overview?view=sql-server-ver16

But there are several things which are not included with contained Availability Groups. click through for that list.

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