SSS: After clearing cache, slightly old rooms (4 days old) take minutes to show up when searching the room list.

[ara4n]

Steps to reproduce

1. I cleared cache to test SSS: Room list doesn't update after initial sync #3089
2. The app took a surprisingly long time to sync (~10s or so)
3. Then, i kept searching the roomlist for a test room which is about 4 days idle. In practice, this means that it's probably 100-200 rooms down my room list.
4. The room didn't show up in the roomlist search results though.
5. I kept searching about 6 times, until eventually it showed up a few minutes after the cache clear.

Outcome

What did you expect?

1. the roomlist search results should warn you if they're incomplete because the list is still being paginated from the server, and avoid the user thinking that the room they're looking for doesn't exist. Shoving a spinner in the search results could be enough.
2. The roomlist should paginate in more rapidly. I'd have expected the first 100-odd rooms to load in a few seconds, not a few minutes.

Your phone model

No response

Operating system version

No response

Application version

679

Homeserver

matrix.org

Will you send logs?

Yes

[ara4n]

Is it possible that the results only turned up once the whole roomlist had been paginated? Which might explain why it took so long.

[Hywan]

It is dynamic. As soon as the room is created, it will appear in your search results. Maybe the server is just slow to give the rooms back: that's the only sane explanations. I'll investigate.

[erikjohnston]

@Hywan is this because when we're growing the room list we set a timeout=30000? As even if you grow the range, if nothing new has happened then the server will still block the request on new data? I could easily imagine it taking minutes to finish growing the list

[ara4n]

if the list has grown, shouldn't it return immediately with the new rooms, despite the timeout?

[erikjohnston]

if the list has grown, shouldn't it return immediately with the new rooms, despite the timeout?

If there are no updates for the rooms now in the range, no we don't. We could try and track changes to the ranges and immediately return if they do, though the clients can also just not set a timeout when growing the lists

[Hywan]

@erikjohnston We can tweak the timeout if that helps. Your suggestion is to lower the timeout or to remove it entirely when the range doesn't cover all the rooms?

[erikjohnston]

@Hywan I would suggest setting timeout=0 whenever the app expects a quick response (e.g. when it would show a spinner, waiting to update the UI, etc). So yeah, I'd probably say that timeout=0 should be set in all states other than Running maybe?