Speaker at European PASS Conference 2008

January 23rd, 2008

As many you probably already know, the Professional Association of SQL Server (aka. PASS) will have an european conference at Neuss, Germany, between April 14 and April 16 this year. The event site http://www.european-pass-conference.com has details about the event, including the agenda, sessions and speakers list. I myself am one of the speakers and I will present techniques for administering, monitoring and troubleshooting Service Broker, with a focus on the new monitoring and troubleshooting tools available for Service Broker in SQL Server 2008.

So if you attend the conference stop by to discuss things Service Brokerish or just to say Hi!

SqlDependency.OnChange callback timing

January 4th, 2008

I had reviewed the way SqlDependency works several times in this blog, but the implementation of this feature will probably continue to surprise me for a long time. After reading about numerous reports of ERRORLOG files getting filled with messages like:

The query notification dialog on conversation handle '{5925E62A-A3BA-DC11-9E8E-000C293EC5A4}.'closed due to the following error: '<?xml version="1.0"?><Error xmlns="http://schemas.microsoft.com/SQL/ServiceBroker/Error"><Code>-8470</Code><Description>Remote service has been dropped.</Description></Error>'.

I decided to take a closer look. The immediate cause of this error is quite clear, is it because the target service of a Query Notification subscription was dropped. I have covered the system error 8470 and others in my earlier post Resending messages. But of course, the real question is why is this happening? Is there some coding error on the part of the application developer and some way to avoid this problem? Is there some configuration issue?

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