A disk issue caused us to temporarily have to utilize a single 10.3.x instance (again with no stability issues).

After we resolved our disk issue, we decided to move to 10.4.7 (since it was the second stable version) and listed on the website as the "stable version".

Unfortunately, nodes in the cluster crash just about everyday.

one node usually fails and then another node drops, with errors like

 190906 14:37:59 [ERROR] mysqld got signal 11 ;

Sep  6 14:37:59 node-2 mysqld[1846]: This could be because you hit a bug. It is also possible that this binary

Sep  6 14:37:59 node-2 mysqld[1846]: or one of the libraries it was linked against is corrupt, improperly built,

Sep  6 14:37:59 node-2 mysqld[1846]: or misconfigured. This error can also be caused by malfunctioning hardware.

Sep  6 14:37:59 node-2 mysqld[1846]: To report this bug, see https://mariadb.com/kb/en/reporting-bugs

Sep  6 14:37:59 node-2 mysqld[1846]: We will try our best to scrape up some info that will hopefully help

Sep  6 14:37:59 node-2 mysqld[1846]: diagnose the problem, but since we have already crashed,

Sep  6 14:37:59 node-2 mysqld[1846]: something is definitely wrong and this may fail.

Sep  6 14:37:59 node-2 mysqld[1846]: Server version: 10.4.7-MariaDB-1:10.4.7+maria~xenial-log

Sep  6 14:37:59 node-2 mysqld[1846]: key_buffer_size=134217728

Sep  6 14:37:59 node-2 mysqld[1846]: read_buffer_size=2097152

Sep  6 14:37:59 node-2 mysqld[1846]: max_used_connections=30

Sep  6 14:37:59 node-2 mysqld[1846]: max_threads=4002

Sep  6 14:37:59 node-2 mysqld[1846]: thread_count=45

Sep  6 14:37:59 node-2 mysqld[1846]: It is possible that mysqld could use up to

Sep  6 14:37:59 node-2 mysqld[1846]: key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 24817728 K  bytes of memory

Sep  6 14:37:59 node-2 mysqld[1846]: Hope that's ok; if not, decrease some variables in the equation.

Sep  6 14:37:59 node-2 mysqld[1846]: Thread pointer: 0x7f32052a0348

Sep  6 14:37:59 node-2 mysqld[1846]: Attempting backtrace. You can use the following information to find out

Sep  6 14:37:59 node-2 mysqld[1846]: where mysqld died. If you see no messages after this, something went

Sep  6 14:37:59 node-2 mysqld[1846]: terribly wrong...

Sep  6 14:37:59 node-2 mysqld[1846]: stack_bottom = 0x7f3271446dd8 thread_stack 0x49000

Sep  6 14:37:59 node-2 mysqld[1846]: /usr/sbin/mysqld(my_print_stacktrace+0x2e)[0x5644f71dcf4e]

Sep  6 14:37:59 node-2 mysqld[1846]: /usr/sbin/mysqld(handle_fatal_signal+0x307)[0x5644f6c70b07]

Sep  6 14:37:59 node-2 mysqld[1846]: /lib/x86_64-linux-gnu/libpthread.so.0(+0x12890)[0x7f33e141d890]

Sep  6 14:37:59 node-2 mysqld[1846]: /usr/sbin/mysqld(handler_index_cond_check+0x8d)[0x5644f6c7b1fd]

Sep  6 14:37:59 node-2 mysqld[1846]: /usr/sbin/mysqld(+0x566623)[0x5644f6973623]

Sep  6 14:37:59 node-2 mysqld[1846]: /usr/sbin/mysqld(+0xbb4ba8)[0x5644f6fc1ba8]

This is getting old and is unlike our usual mariadb experience.

Looking at the jira for 10.4.8, it appears to fix many problems in 10.4 and I'm hopeful it solves this.

In the meantime, any ideas or suggestions for things to look for?

Thanks!