Bug 501965

Summary:	Performance regression: Each action in Korganizer are extremely slow making it unusable
Product:	[Applications] korganizer	Reporter:	Alexandre Bonneau <alexandre.bonneau>
Component:	agendaview (weekview)	Assignee:	kdepim bugs <kdepim-bugs>
Status:	REPORTED ---
Severity:	grave	CC:	winter
Priority:	NOR
Version First Reported In:	6.3.2
Target Milestone:	---
Platform:	Debian testing
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:
Attachments:	screenshot showing the disable icons option

Description Alexandre Bonneau 2025-03-25 03:13:05 UTC

SUMMARY
Each action in Korganizer are extremely slow since the last Debian testing update of kdepim6 in January 2025

STEPS TO REPRODUCE
1. Install Korganizer 6.3.2 in Debian Testing (even as a new user)
2. Configure Korganizer to use your Nextcloud calendar, which has 10k+ elements (tasks and events)

OBSERVED RESULT
- When ever you edit an event/task, move one at a different time slot, or just try to use the mouse wheel on the calendar to change week, it takes several seconds for Korganizer to show the new weekview or the result of your action
- Before it was instant; this hinders its usability _greatly_, to a point it's unusable in a work environment
- Moreover, now when you edit a single event, the whole week is updated, which is very impactful since it moves around all the overdue tasks to the top bar. Before it was better; if you wanted to update the week-view, you had to mouse wheel up then down on the mini-calendar. Your 'missed' scheduled tasks would not move on their own until you decided so.

EXPECTED RESULT
- Instant browsing of the calendar events
- Do not update the week-view when editing a single event/tasks in the view (and by update I mean moving the overdue tasks to the top bar of the current day)
I suspect the fact that Korganizer now updates (in a very badly way performance-wise) every single event/tasks on the current week-view (and perhaps even more), and since I usually have 100+ event/tasks per week, this takes too much time and is very, VERY noticeable.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Debian Testing
KDE Plasma Version: plasma-desktop 4:6.3.2-2+b2
KDE Frameworks Version: plasma-framework 5.115.0-7
Qt Version: 6.8.2
korganizer 4:24.12.2-1
kdepim 4:24.12.2+5.158
kdepimruntime 4:24.12.2-1
akonadiserver 4:24.12.2-1

ADDITIONAL INFORMATION
Linked Debian bug: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1092963

Comment 1 Alexandre Bonneau 2025-03-25 03:17:45 UTC

Also, when trying to move an event with the mouse within a week view, an error is display every single time:
"Erreur lors de la tentative de modification d'un élément de calendrier. L'erreur était : [LLCONFLICT] Resource akonadi_davgroupware_resource_0 tries to modify item 188726 (https://myserver/remote.php/dav/calendars/mycal/cal/1715908932.R453.ics) (in collection 265) with revision 16; the item was modified elsewhere and has revision 17, aborting STORE."
This can be loosely translated to "Error while trying to modify a calendar event. The errar was : [LLCONFLICT]...".

Of course, this item was NOT modified elsewhere; it's just Korganizer doing something wrong.

Finally, do note that if you edit the event by double-clicking it, changing it's day and time, then the modification is ok.

Comment 2 Allen Winter 2025-03-29 12:05:01 UTC

I wonder if querying for the icons slows things.

could you try reverting 16e2d1d94101ca9fadfbdcd63459523a09359883 in eventviews?

Comment 3 Allen Winter 2025-03-29 12:37:16 UTC

oh, you can disable the icons with the setting "Show icons in agenda view items"
see screenshot attachment

Comment 4 Allen Winter 2025-03-29 12:37:53 UTC

Created attachment 179840 [details]
screenshot showing the disable icons option

Comment 5 Alexandre Bonneau 2025-03-30 07:25:25 UTC

I tried disabling the icons in the agenda view, then tried changing weeks, and with and without the icons it takes ~3 seconds (that's a very rough estimation on my part, checking the clock), unfortunately.
This is still infinitely more slow than the instant change before though.

> could you try reverting 16e2d1d94101ca9fadfbdcd63459523a09359883 in eventviews?
I'm not sure what you mean by that

Comment 6 Allen Winter 2025-03-30 11:20:42 UTC

which was the latest version that worked ok for you?

Comment 7 Alexandre Bonneau 2025-03-31 09:01:15 UTC

It's hard to pinpoint exactly, however I first declared the bug the 13th of January on the Debian bug tracker (Korganizer 4:24.12.0-3), and since I use Korganizer pretty extensively, I would have noticed this critical bug right away. Korganizer 4:24.12.0-3 was migrated to Debian Testing the 10th of January, so it tracks.
So according to https://tracker.debian.org/pkg/korganizer, it seems the previous version (that worked ok) to be integrated into testing was Korganizer 4:22.12.3-1, the 2023-03-12...

So a pretty big gap for a dichotomy, sorry