EDIT3: Read-write splitting seems the answer as pointed by out the user dbdemon in the linked question.
Internal MariaDB error code: 1927 ('Connection was killed')
EDIT2: https://drupal.stackexchange.com/questions/68350/high-performance-db-cluster-with-drupal
EDIT: After increasing to 4 cores each node, the log is clearer.
My mariadb cluster is crashing (SIGTERM) or freezing with corrupted data and 100% CPU. The 3 nodes run on 1 core each. I could not find minimum requirements for mariadb,
Is there any way to calculate the required CPU power for mariadb?
References will be appreciated :-)
Edit: The data was not corrupted as far as mariadb/galera were concerned, but seems it was partial since the application (drupal) returned PHP errors (http 500)
The cpu is 2nd generation single thread.
Two nodes serve end-users and one is for internal use, the one for internal use maintained integrity and I could recover from it by dumping and restoring.