When,troubleshooting any issue related to SQL Server, one of the first things we ask the customer  is the SQL Server ErrorLog. Many times, we get the question, where is it located?

There  are several ways to determine the path of the ErrorLog.

 My fellow Microsoft colleague Balmukund has a blog post explaining the various ways to find the path of the ErrorLog. 

https://sqlserver-help.com/2011/06/26/help-where-is-sql-server-errorlog/

Apart from the above described methods, One other way, that we could get the path of the ErrorLog  in SQL Server 2012,when the SQL Server service is running  is through this DMV. 

Sys.dm_os_server_diagnostics_log_configurations

SELECT is_enabled,[path],max_size,max_files

FROM

Sys.dm_os_server_diagnostics_log_configurations

Executing this DMV will give valuable information about the Errorlog  like

•  Path indicating the location of the diagnostic logs.
•  Maximum size in megabytes to which each of the diagnostic logs can grow.
•  Maximum number of diagnostic log files that can be stored on the computer before they are recycled for new diagnostic logs.
•  If logging is enabled or not.

Hope this helps!!

I pondered a lot of time, what should I blog about?

Eventually I came up with this idea of aggregating all the links that I have collected/read about  AlwaysOn Availability Groups.

Why Availability Groups?- It is the hottest topic in SQL Server 2012.

Since it is a new topic, Many database administrators and system administrators will have a lot of questions and hence will search the web for information. So I thought, why not aggregate the information and put it in one place.

I will try to keep the list as updated as possible.

So Here is the List.

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

https://msdn.microsoft.com/en-us/library/ff878487(v=SQL.110).aspx#RestrictionsAG

General Info about Availability groups 

A series of Blog posts about AlwaysOn availability groups from BrentOzar PLF

 https://www.brentozar.com/sql/sql-server-alwayson-availability-groups/ 

https://www.simple-talk.com/sql/database-administration/sql-server-2012-alwayson/

Configuring AlwaysOn with Powershell

https://blogs.msdn.com/b/sqlalwayson/archive/2012/02/03/configuring-alwayson-with-sql-server-powershell.aspx

Availability Group Listener

Video about AlwaysOn Availability Group Listener.

https://blogs.msdn.com/b/sqlalwayson/archive/2012/01/16/introduction-to-the-availability-group-listener.aspx

Creating Multiple listeners for the same availability group

https://blogs.msdn.com/b/sqlalwayson/archive/2012/02/03/how-to-create-multiple-listeners-for-same-availability-group-goden-yao.aspx

Sp_Server_diagnostics

https://blogs.msdn.com/b/psssql/archive/2012/03/08/sql-server-2012-true-black-box-recorder.aspx

Flexible failover policy

https://msdn.microsoft.com/en-us/library/ff878664(v=SQL.110).aspx

Readable Secondary

This Blog post by Remus Rusanu about Availability Groups is simple and easy to understand.

https://rusanu.com/2010/11/11/alwayson-high-availability-and-reads-scale-out/

The AlwaysOn Blog has excellent posts about Readable Secondaries. All the Internals that you want to learn about Active Secondaries
can be found here.(Temporary Statistics, Snapshot Isolation etc...)

https://blogs.msdn.com/b/sqlalwayson/archive/tags/alwayson_3a00_+readable+secondary/

Configuring Secondary Read Only Access

https://www.bidn.com/blogs/PatrickLeBlanc/ssis/2513/alwayson-configuring-secondary-read-only-access

Readable Routing

Blog post about Configuring Readable Secondary routing

https://blogs.msdn.com/b/jtarquino/archive/2011/12/12/configuring-a-readable-secondary-routing-in-sql-server-2012-alwayson.aspx

Wiki Article on Read only Routing

https://social.technet.microsoft.com/wiki/contents/articles/13503.read-only-routing-with-sql-server-2012-always-on-database-availability-groups-en-us.aspx?Sort=MostUseful&PageIndex=1

A Very handy script that will generate the ROR URL for you-  Written By matt Neerincx

https://blogs.msdn.com/b/mattn/archive/2012/04/25/calculating-read-only-routing-url-for-alwayson.aspx

AlwaysOn and Backups

An excellent 3-part series by fellow PFE ,Lisa Gardner on Backups on  Active Secondaries.

https://blogs.msdn.com/b/sqlgardner/archive/2012/07/18/sql-2012-alwayson-and-backups-part-1-offloading-the-work-to-a-replica.aspx

https://blogs.msdn.com/b/sqlgardner/archive/2012/07/21/sql-2012-alwayson-and-backups-part-2-configuring-backup-preferences-and-automating-backups.aspx

https://blogs.msdn.com/b/sqlgardner/archive/2012/08/28/sql-2012-alwayson-and-backups-part-3-restore.aspx

Availability Groups and Kerberos

A blog post by Robert about Using Availability Groups with Kerberos

https://blogs.technet.com/b/rhartskeerl/archive/2012/03/04/kerberos-and-availabilitygroups-what-you-need-to-know.aspx

Asymmetric Storage

Excellent Post by Pareekshit explaining about Asymmetric Storage.

https://www.sqlserverfaq.net/2012/09/16/when-do-we-need-asymmetric-storage-with-alwayson-fci-and-availability-storage/

Converting a Logshipping configuration to availability group

Blog post explaining ,how you can convert your existing Logshipping architecture to an Availability Group Architecture.

https://blogs.msdn.com/b/sqlalwayson/archive/2012/01/09/converting-a-logshipping-configuration-to-availability-group.aspx

Troubleshooting and Monitoring

Joe Sack’s blog post about the various wait statistics associated with Availability groups

https://www.simple-talk.com/sql/database-administration/a-first-look-at-sql-server-2012-availability-group-wait-statistics/

Another blog post by Joe Sack about  Always on Dashboard and the DMV’s behind the dashboard.

https://www.sqlskills.com/blogs/joe/post/Answering-Questions-with-the-AlwaysOn-Dashboard.aspx

Information about the  AlwaysOn Extended Event session –written by Jonathan Kehayias

https://www.sqlskills.com/blogs/jonathan/post/New-AlwaysOn_health-Extended-Events-Session-in-SQL-Server-2012-RC0.aspx

Monitoring with Powershell 

https://blogs.msdn.com/b/sqlalwayson/archive/tags/powershell/

Internals

Various Blog posts by the Customer Service and Support Team about the internals of AlwaysOn

https://blogs.msdn.com/b/psssql/archive/tags/alwayson/

FAQ

Allan Hirt  has an Excellent post on various questions on Availability Groups

https://www.sqlha.com/2012/04/13/allans-alwayson-availability-groups-faq/

My fellow PFE and friend Krishna has an Excellent one line answers for various Questions regarding AG

https://blogs.msdn.com/b/srgolla/archive/2012/09/17/sql-server-2012-always-on-faqs.aspx

Another FAQ blog post about AlwaysOn

https://blogs.technet.com/b/sqlman/archive/2011/08/14/sql-server-denali-alwayson-q-amp-a.aspx

White Papers

AlwaysOn Architecture Guides and Design Patterns

These Guides explain you about the various design patterns you can implement with AlwaysOn

•       
  HA and DR using Failover Cluster Instances.(Multi Subnet)
•       
  HA and DR using using Availability Groups.
•   
  HA using FCI and DR using Availability Groups

https://blogs.msdn.com/b/sqlalwayson/archive/2012/07/03/alwayson-architecture-guides.aspx

Migration Guide:
Migrating to SQL Server 2012 Failover Clustering and Availability Groups from Prior Clustering and Mirroring Deployments

https://msdn.microsoft.com/en-us/library/hh923056.aspx

My name is Karthik Yella. I work as a Premier Field Engineer  for Microsoft. Through this blog,I would like to share my experiences on various topics in SQL Server.