UX Page Property "chrome_main": What are cached and active tabs?

[aasch]

Hey,

tl;dr before diving into context:

• What exactly do the JSON-properties "maxCachedPageCount" and "maxCachedPageCount" do and how should we tune them?
• What are "cached" and "active" tabs exactly?

Context:
I'm currently having a closer look at UX Page Properties and I've come across the "chrome_main" Property.

Doing my due diligence I've read through Ashley Snyder's very thorough post about UX Page Properties and I've done both the UI Builder Fundamentals and UI Builder Advanced courses on SN-University and watched a few of the Academy YouTube videos.

Unfortunately I still don't feel confident in configuring the properties properly.
It seems like there's a significant performance gain if we set both properties to higher numbers. But I'd like to know what they do exactly to judge impact on the system and on people's machines.

To get into the weeds:
In Ashley's post, "maxCachedPageCount" is described like this:
"Indicates the total number of sn-canvas-screen instances live in DOM per experience."

I consider myself a pro-code developer, but I'm not part of the internal development team, so a few questions came to my mind:

• What is an sn-canvas-screen?
• What does it mean for an sn-canvas-screen to be "live" in DOM?
• What happens when it transitions between live and not live?
• Which actions (browser and/or server) does the transition encompass? The word "cache" usually implies either a browser or server cache of content.
• How do I need to tune the property according to my customer's needs (instance speed, User's computer speed)?

"maxActivePageCount" is described as "Indicates the number of active sn-canvas-screens within the dom how many are active".
Similary, a few questions about the specifics come to mind:

• What does it mean for an sn-canvas-screen to be active or inactive?
• What happens on the transtition in the browser/server?
• Does active/inactive differ from being cached and if so, how?
• How do I need to tune the property according to my customer's needs (instance speed, User's computer speed)?

A general thing I noticed is this:
Higher numbers mean way better performance. Setting both properties to 20 for example, significantly improved the experience of switching between tabs. I was able to completely avoid the typical "lag" of about ~1 second that you frequently notice in Workspaces when switching tabs.
The obvious answer to the performance gain would be: More stuff gets "cached" and stays "active". But where? Which type of cache? What is "active" if not "the currently opened tab"?

I'm asking these questions because a "more higher numbers = more better" approach doesn't seem smart when tuning things for larger organizations.

Hopefully someone has some insight into this.

Best regards 🙂