Performance of expanding drop downs

Ben Hayat

Posted on: 23 Apr 2020 20:49

Excellent support and explanation from Marin;

This type of responses gives me confidence using their products;

Thanks!

ADMIN

Marin Bratanov

Posted on: 23 Apr 2020 17:35

Thank you for getting back to me, Rob.

It's after working hours here, so we'll have to wait a bit longer until we can review and fix our server.

With the information so far, I am closing this issue as it did not stem from our components, but from environmental configuration. If you do experience problems with our components, feel free to open a support ticket.

Regards,
Marin Bratanov
Progress Telerik

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Rob

Posted on: 23 Apr 2020 17:33

Thanks Marin, our server had them disabled as well, once enabling we're no longer seeing all of the XHR noise.

I think the slowness we have to deal with now is just the nature of server-side Blazor. I appreciate the quick assistance with this!

Thanks,

Rob

ADMIN

Marin Bratanov

Posted on: 23 Apr 2020 17:25

Hi Rob,

You could open a private support ticket.

I've just reviewed this further (it so happened that we had this investigation scheduled for 25 minutes ago) and it looks like our hosting server has had a hiccup - WebSockets are no longer enabled on it, so SignalR falls back to XHR requests, which are waaay too slow for Blazor (and they also carry cookies which makes them huge, in addition to the heavier request pipeline they trigger). It had seemed that the issue comes from a certain script, but this is not the case, it's our server.

In summary, make sure your server has WebSockets enabled :) For example, Azure hosting does not have them enabled by default.

Regards,
Marin Bratanov
Progress Telerik

Progress is here for your business, like always. Read more about the measures we are taking to ensure business continuity and help fight the COVID-19 pandemic.
Our thoughts here at Progress are with those affected by the outbreak.

Rob

Posted on: 23 Apr 2020 17:08

Marin,

Is there anyway we could take this off of here (maybe through email) so you could help me understand the demo site script issue more? We see what you're describing in regards to the XHR requests any time we're interacting with controls (menus, dropdowns, time pickers, etc.), and it "feels" like where the slowness is coming from. Would just love to rule this same issue out on our end.

Thanks,

Rob

ADMIN

Marin Bratanov

Posted on: 23 Apr 2020 16:45

Hi Rob,

To each point:

local vs internet sites - indeed, that's how the different models are designed. Until the WebAssembly flavor becomes official, we can't consider moving to it, so we're stuck with the server-side flavor for now. For a more realistic experience, you should, indeed, run things locally.
animations - at the moment, you can't disable the animation. It shouldn't be an issue when latency is low, however. When latency is large the animation feels two times slower, which is too slow. With low latency, the animation is crisp and quick, and helps the user track that something is changing on the screen - having one is a general UX best practice.
the demo site script issue - I am not sure I am in a position to comment on that because it might be considered harmful to the vendor's reputation. What I can say is that the issue is that it replays the SignalR binary packets as XHR requests which you can see yourself in the browser console.

Regards,
Marin Bratanov
Progress Telerik

Progress is here for your business, like always. Read more about the measures we are taking to ensure business continuity and help fight the COVID-19 pandemic.
Our thoughts here at Progress are with those affected by the outbreak.

Rob

Posted on: 23 Apr 2020 16:00

Also, could you comment more on the script on the demo site? Just to make sure we don't have something on our site causing the same problem?

Rob

Posted on: 23 Apr 2020 15:59

Right now we're using everything server-side until WASM is officially released. Due to that, you're correct, the slowness is definitely more apparent on hosted sites versus running locally. It may also be the animation of the drop down list that makes it "feel" slower then it is. Is there a way to disable the animation to see if it "feels" faster after that?

ADMIN

Marin Bratanov

Posted on: 23 Apr 2020 15:51

Hello Rob,

To begin with the good news, we are working on improving this the performance of the dropdowns.

That said, in the general case, things should be fine even as it is. I am aware of two cases where issues can manifest:

on our live demos - they are a server-side app, and as such are not actually suitable for a public facing site where many people have a large latency to it. There is also an issue with one of the scripts our marketing team uses that interferes with Blazor and we're working on resolving it, and that slows our demos down too.
So, do you observe such a behavior on localhost or on an intranet hosting? You can also run our demos locally, they are available in your installation folder.
when there are too many items in the dropdown - this is an inherently problematic scenario and for such cases I would recommend implementing custom filtering like here: https://docs.telerik.com/blazor-ui/components/combobox/events#onread. You may also find interesting this feature request that would also improve rendering performance: https://feedback.telerik.com/blazor/1457808-combobox-virtualization

Do you have a different case?

Regards,
Marin Bratanov
Progress Telerik

Progress is here for your business, like always. Read more about the measures we are taking to ensure business continuity and help fight the COVID-19 pandemic.
Our thoughts here at Progress are with those affected by the outbreak.