The Dedicated Administrator Connection

SQLServerCentral is supported by Red Gate Software Ltd.

Popular Topics

Home

Members

Calendar

Who's On

Home » Article Discussions » Article Discussions by Author » Discuss Content Posted by Wayne Fillis » The Dedicated Administrator Connection

The Dedicated Administrator Connection

Rate Topic

Display Mode

Topic Options

Author

Message

Wayne-153714

Posted Friday, December 29, 2006 11:35 AM

SSC-Enthusiastic

Group: General Forum Members
Last Login: Thursday, October 04, 2012 6:40 AM
Points: 143, Visits: 54

Comments posted here are about the content posted at http://www.sqlservercentral.com/columnists/WFillis/2786.asp

When in doubt - test, test, test!

Wayne

Post #333518

philcart

Posted Tuesday, February 06, 2007 1:32 AM

SSCrazy

Group: General Forum Members
Last Login: Friday, May 17, 2013 5:53 AM
Points: 2,692, Visits: 1,074

What do you do when you can't connect using the DAC ??

We had a problem on a clients server recently and the CPU was flatlining. We could tell from Task Manager that SQL was the process consuming the CPU. Connecting to SQL using SQLCMD or Management Studio resulted in a rude timeout error.

As we couldn't connect to the server, we couldn't do any diagnosis to determine the reason for the flatline.

Hope this helps
Phill Carter
--------------------
Colt 45 - the original point and click interface

Australian SQL Server User Groups - My profile
Phills Philosophies
Murrumbeena Cricket Club

Post #342665

Wayne-153714

Posted Tuesday, February 06, 2007 2:46 AM

SSC-Enthusiastic

Group: General Forum Members
Last Login: Thursday, October 04, 2012 6:40 AM
Points: 143, Visits: 54

If you can't connect remotly, or via DAC then try locally on the server itself. If you still can't connect the only thing I can think of is to restart the SQL instance.

Check your recompiles - use perfmon, under SQL Server: Statistics take a look at Batch Requests, Compilations and Recompilations. Compiling takes CPU, which unavoidable. Recompilations are a problem - if you are using embedded SQL try switching to stored procedures.

Analyse master.dbo.syscacheobjects to see if objects are being dropped from the procedure cache due to memory contention.

Also run profiler, and trace recompilations to see what code is causing recompilations (if you think that is causing your CPU).

Another possibility for high CPU is corrupted software and drivers. I know the guys here had an old version of a Java ODBC (JDBC?) driver that caused CPU to spike. A upgrade fixed the problem. Check google.

When in doubt - test, test, test!

Wayne

Post #342686

Susan Van Eyck

Posted Tuesday, February 06, 2007 6:31 AM

SSC-Addicted

Group: General Forum Members
Last Login: Yesterday @ 1:26 PM
Points: 489, Visits: 173

DAC is available in Express, it's just disabled by default.

http://blogs.msdn.com/sqlexpress/archive/2005/09/08/462609.aspx

Steps to enable DAC in Express:
1) Launch Services Applet in Control Panel
2) Stop SQL Server Express Service
3) Launch Properties dialog of SQL Server Express Service
4) Add "-T7806" to the startup parameters
5) Start the SQL Server Express service

Post #342750

Steve Jones - SSC Editor

Posted Tuesday, February 06, 2007 7:17 AM

SSC-Dedicated

Group: Administrators
Last Login: Yesterday @ 2:54 PM
Points: 31,410, Visits: 13,726

Phil,

If you can't connect, I'd contact MS immediately. You could try running SQLDiag, but that might fail as well.

Follow me on Twitter: @way0utwest

Forum Etiquette: How to post data/code on a forum to get the best help

Post #342765

Nick Miller-399759

Posted Tuesday, February 06, 2007 3:58 PM

Forum Newbie

Group: General Forum Members
Last Login: Wednesday, August 29, 2007 1:04 PM
Points: 1, Visits: 1

Does anyone know if the DAC works or can be enabled in SQL 2005 Developer Edition?

I've tried enabling Remote DAC and -T7806. SQLCMD reports "Sqlcmd: '-A': Unexpected argument." and Management Studio simply reports reports "Dedicated administrator connections are not supported. (Object Explorer)".

I didn't know if there might be a way to enable it.

Post #342951

Wayne-153714

Posted Wednesday, February 07, 2007 5:29 AM

SSC-Enthusiastic

Group: General Forum Members
Last Login: Thursday, October 04, 2012 6:40 AM
Points: 143, Visits: 54

You can't use DAC with Object Explorer in SSMS. You can only use a query window with DAC in Management Studio.

Try running SQLCMD locally.

Are you specifying servername when you run SQLCMD?

When in doubt - test, test, test!

Wayne

Post #343072

Sundar-242319

Posted Monday, January 14, 2008 12:55 PM

Forum Newbie

Group: General Forum Members
Last Login: Tuesday, January 22, 2013 8:41 AM
Points: 1, Visits: 40

Thanks SSC-Enthusiastic.

In SSMS instead of connecting to database engine directly select the new query and connect as admin:server and it connects to master in query mode.

Post #442645

« Prev Topic | Next Topic »

Permissions