Re: javascript files not cached

Anonymous · ‎10-28-2021

I have been looking into the performance for some of our reports on our local PowerBI Report Server and noticed that a couple of the javascript files is downloaded on each page request. The files are from what I can see static and not changed over time.

These files are loaded from a hidden iframe with the source VisualResourceLoader.htm and is even added twice to the DOM. So the client have to download all of these files two times.

In the response headers I can see that the files have not been modified since 25 May 2021 and they have the no-cache header with an ETag which should mean that the client can use its local file if they match.

We currently use the PowerBI Report Server 2021 May in production but I have also tested this on the September 2021 release with the same result.

Could you please look into why these files are loaded twice and not are cached.

PowerBI Report Server Version:

Version 1.11.7815.26414 (May 2021)

Ben047 · ‎12-03-2023

@Anonymous wrote:
I have been looking into the performance for some of our reports on our local PowerBI Report Server and noticed that a couple of the javascript files is downloaded on each page request. The files are from what I can see static and not changed over time.
These files are loaded from a hidden iframe with the source VisualResourceLoader.htm and is even added twice to the DOM. So the client have to download all of these files two times.

In the response headers I can see that the files have not been modified since 25 May 2021 and they have the no-cache header with an ETag which should mean that the client can use its local file if they match.
We currently use the PowerBI Report Server 2021 May in production but I have also tested this on the September 2021 release with the same result.

Could you please look into why these files are loaded twice and not are cached.

PowerBI Report Server Version:
Version 1.11.7815.26414 (May 2021)

I have the same problem, is there any update about this issue?

the PBI report server i used is 2023-01

Anonymous · ‎11-01-2021

Hi Henry,

The reports I have looked at is created using PowerBI not SSRS so the first link should not solve my issue. I have seen the second link and that is similar to what I have found. But as noted in that post most of the javascript-files are beeing cached and I can see that I get 304 responses for them.

But the javascript files loaded from the hidden iframe with the source VisualResourceLoader.htm is not cached.

I did try to use the CustomHeaders config to cache the files myself, but did not succed.

Best regards,

Tobias

v-henryk-mstf · ‎11-01-2021

Hi @Anonymous ,

The report server can cache a copy of the processed report and return that copy when the user opens the report. However, when a certain amount of time has elapsed, the data model corresponding to the report is removed from memory.

You can refer to the relevant documentation and similar scenarios.

Caching Reports - SQL Server Reporting Services (SSRS) | Microsoft Docs

Solved: PowerBI report server Cache-Control: no-cache - Microsoft Power BI Community

Best Regards,
Henry

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