Lots of MariaDB binary logs


I’m currently managing 1660 hosts, spread onto two masters sharing a database.
For about two to four weeks, I notice a large amount of MariaDB binary logs (60GB in two days).

I don’t think this is normal as some weeks ago, it only needed about 10GB in a week and the automatic cleanup removed old ones.

The whole database looks like this:
root@mariadb01 /var/lib/mysql # du -h --max-depth=1
608K ./mon_reporting
11M ./mysql
2.7G ./mon_icinga2_ido
526M ./mon_director
16K ./lost+found
1.1M ./mon_x509
8.0K ./performance_schema
440K ./mon_icingaweb2
7.4G .

Where do I need to search?

Thank you.