Slaves are going to wsrep_ready off state and 'show full processlist' shows 'truncate'. This happened until we replaced 'truncate custom_apps_rules_pending' with 'DELETE FROM custom_apps_rules_pending'
Error log output
2020-10-20 15:57:41 0 [Warning] WSREP: server: mariadb02 unallowed state transition: disconnecting -> disconnecting
mysqld: /home/buildbot/buildbot/build/mariadb-10.4.7/wsrep-lib/src/server_state.cpp:1296: void wsrep::server_state::state(wsrep::unique_lock<wsrep::mutex>&, wsrep::server_state::state): Assertion `0' failed.
201020 15:57:41 [ERROR] mysqld got signal 6 ;
This could be because you hit a bug. It is also possible that this binary
or one of the libraries it was linked against is corrupt, improperly built,
or misconfigured. This error can also be caused by malfunctioning hardware.
To report this bug, see https://mariadb.com/kb/en/reporting-bugs
We will try our best to scrape up some info that will hopefully help
diagnose the problem, but since we have already crashed,
something is definitely wrong and this may fail.
Server version: 10.4.7-MariaDB-1:10.4.7+maria~xenial-log
It is possible that mysqld could use up to
key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 110050057 K bytes of memory
Hope that's ok; if not, decrease some variables in the equation.
Thread pointer: 0x0
Attempting backtrace. You can use the following information to find out
where mysqld died. If you see no messages after this, something went
stack_bottom = 0x0 thread_stack 0x30000
The manual page at http://dev.mysql.com/doc/mysql/en/crashing.html contains
information that should help you find out what is causing the crash.
Writing a core file...