Review how we deal with a large amount of tabs

[fregante]

With some people hoarding tabs, injection and broadcasting could stall the browser or take several seconds.

Is there anything we can do in this area?

Some thoughts:

• anonymously collect number of tabs
• report back when broadcasts affect more than 20 tabs
• notify user when a run affects a large number of tabs
• stagger broadcasting
• exclude discarded tabs

Some operations that involve opening tabs could also have such limits in place, you wouldn't want to run the blueprint open every link on a wikipedia page in a new tab

[fregante]

cc @twschiller is there anything actionable here to diagnose the performance issues?

[fregante]

I think this compounds with #6548, especially for users who never restart their computer. Imagine a tab hoarder with 100 tabs open and none of them is connectable. Any broadcasted message will be sent up to 700 times in 10 seconds.

[twschiller]

I agree that this is a good issue to keep in mind. The internal users who tend to have performance issues do have a lot of tabs open

However, excess tabs should only impact:

• Memory usage
• Broadcast performance (broadcast isn't common in mods though)

Just having a tab open shouldn't generate background traffic/extra background work utilization if no mods are running on that tab

I think this compounds with #6548, especially for users who never restart their computer.

Brainstorming:

• To avoid retries to dead tabs, we could snapshot which tabs were open at the time of install and mark those as do-not message (or only message once) until we see a full navigation event for the tab
• See comment here on pinging for potential liveness: Investigate delayed execution of bricks in resource-starved browsers #6581

cc @BLoe @grahamlangford

[fregante]

Brainstorming: by @twschiller

• Pre-existing tabs access tracked in Existing tabs are not connectable after an install or extension update #6548
• Discarded tabs were excluded in Don't retry on discarded tabs webext-messenger#163

Some thoughts: by @fregante

Some thoughts:

• anonymously collect number of tabs
  • I guess not
• report back when broadcasts affect more than 20 tabs
  • I will add reportEvent('broadcasted to', x, 'tabs')
• notify user when a run affects a large number of tabs
  • I don’t think each broadcasted brick should actually add a notification on screen so I'll look into logging maybe?
    • Add "Broadcasted to 30 tabs" warning to Mod "logs", if possible.
• stagger broadcasting
  • This might make sense, but I assume it's not necessary.

I'll try to finalize this issue next week. Let me know if you have reservations.

[fregante]

I opened a PR for the first and an issue for the second:

• Report PerformanceMessengerManyTabsBroadcast event #6963
• Add "Broadcasted to 30 tabs" warning to Mod "logs" #6964