Bug 458872

SUMMARY
On computers where an MS Exchange account is registered into Kmail (or possibly any other application using the Akonadi service) when the machine is off the internet high CPU usage is observed in the processes kioslave and akonadi_ews_resource.

I would like to emphasize that I have two additional virtual networks available, one for docker containers and another for QEMU virtual machines, which are both not on the internet.

Potentially related, many attempts at connecting to the EWS server, which promptly fails. This causes many log messages to be written with the label org.kde.pim.ews.client, eventually filling up /var/log and therefore my root partition. I have not been able to reproduce this issue locally again in order to provide newer journal entries.

This is an example of the message being generated (many times a second)
kalendarac[2118]: org.kde.pim.ews.client: Failed to process EWS request: Unknown host <hostname redacted>: Host not found.

STEPS TO REPRODUCE
1. Register a Exchange Account with any KDE application.
2. Take machine offline.
3. Observe the journal and process CPU usage.

OBSERVED RESULT
High CPU usage and many journal entries with the EWS host being not found.

EXPECTED RESULT
Lower CPU usage and not as many log events.

SOFTWARE/OS VERSIONS
Operating System: Debian GNU/Linux
KDE Plasma Version: 5.25.4
KDE Frameworks Version: 5.97.0
Qt Version: 5.15.4
Kernel Version: 5.18.0-4-amd64 (64-bit)
Graphics Platform: Wayland

ADDITIONAL INFORMATION
Due to my limited connectivity, I may not be able to provide some details this week. I'll happily cooperate as much as I can when possible.