Today our database server crashed and we lost all our 12 wordpress sites. In the mariadb.err file, we have 100's of error like this before and after the crash.

2019-10-15 12:57:35 34895617536 [Note] Suppressing warnings of type 'Statements writing to a table with an auto-increment column after selecting from another table are unsafe because the order in which rows are retrieved determines what (if any) rows will be written. This order cannot be predicted and may differ on master and the slave.' for up to 300 seconds because of flooding

2019-10-15 12:57:47 34897067776 [Warning] Unsafe statement written to the binary log using statement format since BINLOG_FORMAT = STATEMENT. The statement is unsafe because it uses a LIMIT clause. This is unsafe because the set of rows included cannot be predicted. Statement: UPDATE gjs_posts SET post_password = 'c69ba47391635ebd4e58', post_modified_gmt = '2019-10-15 12:57:47', post_modified = '2019-10-15 12:57:47' WHERE post_type = 'scheduled-action' AND post_status = 'pending' AND post_password = '' AND post_date_gmt <= '2019-10-15 12:57:47' ORDER BY menu_order ASC, post_date_gmt ASC, ID ASC LIMIT 25

Could anyone tell me if this is a normal wordpress begavior of if it is a hack attempt?

On the host, I also got this error:

Oct 15 12:35:41 FreeBSD-node1 kernel: sonewconn: pcb 0xfffff80643972600: Listen queue overflow: 193 already in queue awaiting acceptance (28 occurrences)

Thank you