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Tuesday, April 26, 2011

Capturing Time-Out Procedures using Extended Events

Due to various reasons, your procedures will fail after time out period elapsed.

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But with the above generic error message, it is difficult to find out which procedure was failed.

Obvious way to find out timing out procedures are to debug your code. However, sometimes you might not be able to create this issue in your environments, since time-out error might depend on the environment setting or environment data.

So let us create a procedure which will time out.

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Since this proc is having a delay for 20 hrs, it will obviously will fail with time out.

Let us call this procedure from C# application.

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Though profiler can be used to capture this, running profiler may decrease your system performance. Microsoft introduced Extended Events to SQL Server, calming it is a light weight monitoring

In extended event, there is an event type called Event pairing, shows incomplete events. There are some events which are pairs such as lock acquired and lock released and from this event type we can capture incomplete events.

In our scenario, paired events are sp_statement_starting and sp_statement_completed and in case of a timing out, sp_statement_Completed event will not be completed.

You can create a extended event like following/

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Then we can capture the event by running following query.

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This result will give you

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This means, though there are 11127 matched events, there is one orphan event which is what we are after.

If you expand the XML, it will give you the database id and the object id from which can find the culprit.

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Interesting thing here is, sql_text is shown as Unable to retrieve SQL text, but if you execute this proc in SSMS, you will see the relevant proc in this XML it self.

Thursday, April 21, 2011

Monday, April 18, 2011

Using SQL Server Resource Governor to Control Resource Utilization

This article introduces SQL Server Resource Governor and provides a detailed walkthrough of using Resource Governor to manage the resource utilization of SQL Server.

Saturday, April 16, 2011

Removing History of Database Mail Log

You might know that it is possible to remove history of an Agent Job history.

 

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If you right click the Agent properties and select History. There you have a configuration to limit you job history.

If you go to the Database mail history, you will see that above setting does not delete the database mail log.

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So question is how we can delete the database mail log so that it can be maintained.

well, there is no user interface for that. Embarrassed smile  However, in SQL Server there is a in built procedure in MSDB database called sysmail_delete_log_sp

This proc has two default parameters, @logged_before (datetime)  and @event_type (varchar(15)) and both has default values of null.

so, if you simply execute sysmail_delete_log_sp it will simply delete entire log.

if you pass the date for the @logged_before  , your database mail log data before that will be deleted.

sysmail_delete_log_sp @logged_before = '2010-12-31' 

Above will delete all the log data before 2010-12-31.  

If you want to delete data until up to last seven days, you can execute following.

 
DECLARE @dt DATE =  DATEADD(d,-7,GETDATE())

EXEC sysmail_delete_log_sp @logged_before = @dt
 
Also, you can delete database mail log based on the event type as well. You can pass Success, Information or Warning. 
if anything else other than NULL is passed it will be treated as Error.