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gustavjMC
Frequent Visitor

Slow initial load

Hello!

 

I've created a PowerBI report that I previously had some performance issues with. I've now corrected all of those performance issues and have < 7 seconds of waiting time on each report page. The problem however still exist when you enter the report for the first time in a while (a couple of hours is most of the time enough). The report is using DirectQuery for most of the pages.

 

I have another report that uses 100% import mode and that report is fast, even when I visit it for the first time in a while.

 

Is there anything I can do with my report to make it faster? It has a fast loading time in PowerBI Desktop and in PowerBI service in general, it's just that first initial load in PowerBI service that's slow.

6 REPLIES 6
gustavjMC
Frequent Visitor

Thank you for the tips and tricks!

 

Unfortunately none of them works for me. The problem with my report isn't that it's generally slow because generally, it's quite fast. The problem for me only exists when I open the report for the first time of the day in Power BI service. It's fast in Power BI Desktop and fast in Power BI service when it's not the first time I visit it for the day (or atleast for at couple of hours). 

 

It's really hard to troubleshoot this problem because it does as I said only occur when visiting the report for the first time in a while or directly after i published a new version of the report from Power BI Desktop. 

 

Is there any visuals or something that is only downloaded when visiting the report for the first time in a while or where is this problem coming from?

HI @gustavjMC ,

 

Yes, when you first open the report, it loads into memory and runs on your machine to get the data ready to use.  This is standard.  If it is slow during this part that means that you have either an incredibly massive dataset or you have inefficient queries or you have lots and lots of Power Query edits that it runs through, or you have a very slow and underpowered machine, or you have a slow network or any of the other things that myself or @v-yangliu-msft suggested.

Once it is loaded, it will run fine and quickly.

If it really takes a couple hours to get ready to use then you need to re-evaluate all of these options to get this to be a more effective report.  Or, you can just live with the fact that this is how long it takes.

I would appreciate Kudos if my response was helpful. I would also appreciate it if you would Mark this As a Solution if it solved the problem. Thanks!




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Hi @collinq 

 

Thank you for your answer!

 

Just to be clear, it doesn't take a couple of hours for the report to get ready to use. When i say slow, I mean like 20 seconds. 

 

EXAMPLE:

 

  • I visit the report at 07:00 in the morning, the report takes about 20 seconds to load and then I can browse the report's all pages without significant loading time.
  • I visit the report an hour later, 08:00 in the morning. The report is now fast even though it is updated with new values since last time i visited the report.
  • I visit the report two hours later at 10:00 and the report is still loading very fast.
  • I wait 7 hours and opens the report at 17:00, the behaviour of the report is now like it was in the morning. It's taking about 20 seconds to do an initial load and then I can browse and update the values very fast.

 

I hope this example makes it more clear what my problem really is 🙂

v-yangliu-msft
Community Support
Community Support

Hi  @gustavjMC  , 

To optimize report loading, you can try the following operations:

1. Check the refresh summary and the metric usage app to view the refresh time, allocate reasonably, and try to choose the idle time to refresh. The refresh time with centralized refresh time is divided equally, so as to avoid too many people occupying resources and causing queuing

2. Select the correct capacity. For those datasets whose data refresh time reaches 2 hours, place them in the premium capacity, and the maximum refresh time is 5 hours

3. Remember the refresh limit. When the source data source is frequently refreshed, choose the DQ / LC mode as much as possible, because the import mode will constantly refresh the data set of the import mode and occupy resources. However, DQ / LC will limit the number of rows of returned data to 100W, and the corresponding time limit for running query is 225 seconds, which is more effective for refreshing

4. Optimize the tables and columns used by datasets and reports or instruments, avoid using complex DAX functions and delete useless fields

5. Limit the number of visual objects on the dashboard rather than using RLS

6. Use a reliable on premises data gateway to prevent the report from being unavailable or overloaded and failing to refresh the report. It also ensures that the physical machine configured with the gateway is not far away from the physical machine using the gateway, so as to avoid the geographical location from affecting the speed

7. Go to capacity setting and select a capacity node. Look at the workload settings. Adjust the resource allocation of the dataset to a small extent and the resource allocation of the dataset to a higher level

 

This is the related content and video about the problem, hope to help you:

https://docs.microsoft.com/en-us/power-bi/guidance/power-bi-optimization

https://docs.microsoft.com/en-us/power-bi/guidance/report-performance-troubleshoot

https://www.youtube.com/watch?v=vbS7WuH6PO8

 

Best Regards,

Liu Yang

If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

collinq
Super User II
Super User II

HI @gustavjMC ,

 

You could open the Query Analyzer and see what is doing (or not doing).  If you don't find anything obvious there, you could do a network trace (like with fiddler) to confirm that everything is communicating as expected.  

I would appreciate Kudos if my response was helpful. I would also appreciate it if you would Mark this As a Solution if it solved the problem. Thanks!




Did I answer your question? Mark my post as a solution!

Proud to be a Datanaut!
Private message me for consulting or training needs.




Hi @collinq ,

 

By Query Analyzer, do you mean the performance tool in Power BI that u can use to track the querys? Because I've already done that and analysed my querys in DaxStudio, everything looks ok there. 

 

I can refresh the data very fast in power bi service so I can't really see in what way my querys could be the problem here. It's only that first initial buffer in the service that is slow. 

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