Timeline: Performance on first render is extremely slow

[levzem]

Hi,

I am working with timeline (4.20) in chrome 59 on windows 7. I am working locally though, and not on an actual website.

I am working with extremely large datasets and large amounts of groups (~40 groups with an additional nested group for each and 30K - 80K items).

It is my understanding that the timeline only loads the visible items to enhance performance. I set limits on the start and end date as well as the max zoom level. I am happy with the scrolling/moving performance, however, when I first load the timeline. it takes an extremely long time to actually first generate the timeline (5 minutes for 30K items, 15+ minutes for 80K items) even when the visible items on the timeline are incredibly low (4 items).

Your examples load quite quickly for 100K items (~10 seconds) and a simple JSBin program from #3248 does it in about ~20 seconds. Attached for reference -> https://jsbin.com/jupelipala/edit?html,js,output

Is there something I can do to improve my own performance or is this an issue that the timeline initially loads all items regardless of visibility?

Thanks

[bradh]

I'm not sure I understand the difference between your case and the performance test examples. Can you try to explain that a bit more?

[levzem]

The problem is that the initial loading/generation of the timeline is slow (performance after the fact is satisfactory).

If I run the same exact code from JS Bin locally from my machine, it takes an extraordinary amount of time, but on JS Bin, it runs pretty quickly. If I run the example code from the visjs.org locally even with many groups (40), it is pretty quick. Likewise, my code renders the timeline slowly as well. I am not sure where this difference comes from.

[bradh]

So its really only slow on your machine? That is going to be quite hard for us to debug. Anything unique that you can suggest might be related?

[mojoaxel]

I can confirm this as a "problem". See also #3248

[levzem]

When do you approximately think that you will be able to resolve this issue?
Is there any fix that I can do in the meantime?

Thanks

[levzem]

It appears that providing a reasonable start and end time in the options resolves all issues for anyone with the same problem. It can be marked as not a problem as along as this is strictly document that start and end are necessary for performance.

[mojoaxel]

I can confirm that setting a start and end improves performance very much.
We should have a look at this fixing #3248 !

We also should add a hint to the docs, that a missing start/end date can reduce performance.

[yotamberk]

Will be added to docs

[abrander]

In a project struggling with slow timeline performancewe did the following trick. Maybe it can help you too, @levzem

gansoi/gansoi@db825cb

[wimrijnders]

@yotamberk Does #3475 fix this? If so, can you put a 'fixes' tag into that PR?