Derik Hammer

Derik Hammer

Synchronizing SQL Server Instance Objects in an Availability Group

September 8, 2017 by

Availability groups can no longer be considered new. The feature was released in SQL Server 2012 but I often notice that SQL Server Failover Cluster Instances (FCIs) are much better understood. For a very long time, when people thought about SQL Server they thought about the entire instance as a unit. Microsoft has been implementing new features and services which begin to segment the concept of an instance from the concept of a database.

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Measuring Availability Group synchronization lag

August 9, 2016 by

With all of the high-availability (HA) and disaster recovery (DR) features, the database administrator must understand how much data loss and downtime is possible under the worst case scenarios. Data loss affects your ability to meet recovery point objectives (RPO) and downtime affects your recovery time objectives (RTO). When using Availability Groups (AGs), your RTO and RPO rely upon the replication of transaction log records between at least two replicas to be extremely fast. The worse the performance, the more potential data loss will occur and the longer it can take for a failed over database to come back online.

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Multiple Server Management – Finding the Database Server

May 6, 2015 by

Every organization has at least one of those guys. You are the guy if you have been with the company long enough that you are very familiar with all of the servers in multiple environments. You can easily translate the SharePoint server into its server name, CL-DB-001-B\SP_2010 and you know all of the DNS aliases pointing to that server as well. Your super power also makes you a magnet for everyone in IT to come and ask you where this database is and what is on that server.

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Disaster Recovery Planning with Always-On Availability Groups

December 17, 2014 by

When I configured my first Always-On Availability Group, I setup a Windows Cluster and started with SQL Server Management Studio’s New Availability Group Wizard, scripting out the steps along the way. This entire process took only a matter of minutes. The minimum required steps for configuring the cluster and getting a database into an Availability Group (AG) are very few. This process, however, is deceptively simple. What some don’t realize is that the majority of work required for setting up an AG needs to occur in the planning phase, before a server is even requisitioned. Let us examine the questions that you should ask before implementing an AG.

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Backup testing with PowerShell – Part 2: Reporting results

October 22, 2014 by

Now that Karla’s restore process is mature, it is time to pre-stage the means of reporting on these events. Two major actions have been taken for each database tested. First a restore operation occurred. The restore operation validates that the backup file is well formed and that there is nothing wrong with the data which would cause a failure. Next CheckTables was executed to thoroughly inspect for data corruption and any consistency errors. Each of these two actions will have their own methods of providing evidence of successful completion. Recall the requirements set by Karla, in part 1 of this series, for the reporting piece. Read more »

Backup testing with PowerShell – Part 1: The test

October 21, 2014 by

Karla is a production database administrator and she has a lot in common with you. Being responsible for database backups and recovery, she has implemented a well-structured automated backup system. Maybe she’s using Ola Hallengren’s Maintenance Solution, custom T-SQL stored procedures, or a set of PowerShell scripts. She has heard the saying, “a DBA only needs one thing, either a backup or a resume, but never both,” and is confident that she won’t be dusting off the resume any time soon. Read more »