Approach to irregular performance problems

Hello there,

now and then we have some performance problems in our application (deployed or localhost).
Config: IIS Version 10 on Windows Server 2019, SQL-DB on SQL Server 13.

In Chrome Developer Tools, I measured up to 20s of TTFB-time for one pageload. It doesn't matter if it is a complex page with e.g. many invokes for dropdown-datagrids or not.

Furthermore it can happen that when calling a dataset from a datagrid 10 times, no performance problems can be detected. On the 11th time there is again a high TTFB-time.

I am aware that this is hard to define, but maybe you know from experience about problems between IIS and SQL Server or there are tips for a better structuring of pageloads.

Thanks in advance,


Hi @mkfromhighlands,

Can you check how much time it takes SQL Server to execute the query in such cases? Maybe your server is busy with something else?

Thank you for your answer, I checked performance monitor on SQL Server while a performance problem occured in the application: nothing special to see. SQL Server is also almost idle since it is part of a testing environment.

Maybe any other suggestions?


We had "Enable Session Refresh" in Radzen Security enabled.
After deactivation, the performance problems are gone.

@enchev: Thank you for your patience!