How to debug with Vaadin 23.3.8?

I have to debug our Vaadin Components due to extreme performance issues. Loading is sometimes super super slow. It is totally random. Sometimes it is fast and sometimes it is loading and loading and you could wait or push some times F5 to make Vaadin work again. It is super weird and it is totally blackbox developing. We just don’t know what happened here. Unfortunately this project is way too big to rebuild it in another framework/language like React. But if this is not fixable, we have to think about leaving Vaadin behind.

Now we thought giving debugging a try. But the documentation for the debug mode / debug window of Vaadin is only for Version 8 (Debug Mode and Window | Advanced Topics | Framework | Vaadin 8 Docs) and there is no debug explanation in the lastest versions documentation.

Even though it is super old, I tried the explanation for the debug mode of V8. And after all setup and adding the suffix “/?debug” to my URL, I don’t see anything looking like a debug tool. There appeared a small button at the bottom right corner which says: “Vaadin development mode initialized”. But it just do nothing I think …

This is the appeared button, which is (as far as I think) not the debug tool.
Screenshot 2024-06-20 151543

Sorry I cannot upload more than one picture in one post, since it is not allowed to new users …
Screenshot 2024-06-20 151548

Screenshot 2024-06-20 151554

I enabled everything just to give them a try … in the beginning everything was disabled
Screenshot 2024-06-20 151558

None of those features are related to performance monitoring. You need to hook up with your favourite IDE and e.g. add break points or monitoring with Prometheus or other tooling to identify the real culprit.

There is also a Vaadin Observability tooling which could be used to also find problems in the frontend; but the beginning would be: make sure your java side is good.

Okay then I will first check our backend. Thank you :slight_smile: