Question

Typical Event Log message looks like below. There you can find very interesting fields „Event occurrence“ and „Event sequence“. What they are means?

In my situation I have exception with event occurence 5, but I can just find only one request in IIS log with 500 status code with URL exactly like in request information in the event log message.

So, how the value of this field calculates? How can I use it?

Event code: 3001  
Event message: The request has been aborted.  
Event time: 5/23/2011 11:35:36 PM  
Event time (UTC): 5/24/2011 3:35:36 AM  
Event ID: 9e8d8159c90349de8f7a6132ed871992  
Event sequence: 65374  
Event occurrence: 5  
Event detail code: 0    
Application information:      
Application domain: /LM/W3SVC/14/ROOT-1-12950413213497090109      
Trust level: Full      
Application Virtual Path: /      
Application Path: E:\wwwsites\MySupaSite\      
Machine name: WEB02    
Process information:      
Process ID: 12228      
Process name: w3wp.exe      
Account name: IIS APPPOOL\MySupaSite    
Exception information:      
Exception type: HttpException      
Exception message: Request timed out.    
Request information:…

Answer 1

Event Occurence is one of the fields that are provided by ASP.NET 2.0 Health Monitoring

ASP.NET 2.0 Health monitoring accumulates events and writes them to the Event Log only if a (configurable) number of occurrences of a specific event is reached.

See also: section <profiles> in ASP.NET 2.0 Health Monitoring – Step 3. Configure Health Monitoring

Update:

Great FAQ on ASP.NET Health Monitoring (ASP.NET Forum) (Just learned a bit here myself *g*) –
which lead me to
MSDN: WebBaseEvent Members
where you can find the exact data types of all its properties