One of my friends, Francesco Reinerio, with KDE, has a software called `baloo` that was flooding `/var/log/messages` with thousand of these lines:
```
org.kde.baloo.engine: PositionDB::put MDB_BAD_TXN: Transaction must abort, has a child, or is invalid
```
Solved cleaning its damn indexes:
```
rm -rf ~/.local/share/baloo
```
I want to share this experience because it was really nasty. The log was 20G.
It was not so immediate to troubleshoot because we didn't know anything about baloo internals.
Reference:
https://forums.mageia.org/en/viewtopic.php?f=7&t=12967