SqlClientDiagnosticListener - change how we measure duration

Reported via discuss

• Currently we use Statistics.ExecutionTime in SqlClientDiagnosticListener to get the duration of the given span for a given sql call.
• This value seems to be an aggregated value of multiple statements - I don’t fully understand how it’s aggregated yet, but as it seems it’s not a 1-1 mapping to spans we generate. Maybe this part needs to be researched and understood a little bit better.

Suggestion for the fix:

• Let’s just rely on the internal timing of our Span type. So instead of getting the duration via the diagnostic source listener, we can just measure it as we do for spans by default.

If someone picks this up: please also try to add a test for this.

[bertvan]

Ok, I reproduced locally with a query like SELECT getdate();WAITFOR DELAY '00:00:01.000'; which showed the issue nicely. I’ll setup something along those lines, with a shorter delay.

[bertvan]

Hi, I’m having a look at the fix this week.

As to why it’s aggregated: https://learn.microsoft.com/en-us/dotnet/framework/data/adonet/sql/provider-statistics-for-sql-server

Returns the cumulative amount of time (in milliseconds) that the provider has spent processing once statistics have been enabled, including the time spent waiting for replies from the server as well as the time spent executing code in the provider itself.