It is possible that we are encountering the OOM issue as the syslog messages had:
Out of memory: Kill process 28080 (mysqld) score 980 or sacrifice child
Killed process 28080, UID 498, (mysqld) total-vm:34727848kB, anon-rss:24101248kB, file-rss:1244kB

system currently has 24Gb of RAM and 2 CPU.

I am posting the values of my.cnf below, may be you will be able to pinpoint something that may trigger this issue.
*****
[client]
user                              = root
port                              = 3306
socket                            = /var/lib/mysql/mysql.sock

[mysqld_safe]
user                              = mysql
pid-file                          = /var/lib/mysql/mysqld.pid
socket                            = /var/lib/mysql/mysql.sock
port                              = 3306
basedir                           = /usr
datadir                           = /var/lib/mysql

expire_logs_days                  = 3
general_log                       = 0
general_log_file                  = /var/log/mysql/mysql_general.log
log-error                         = /var/log/mysql/mysql_error.log
log-bin                           = /var/lib/mysql/mysql_bin
log_slave_updates
skip_slave_start
slow_query_log                    = 1
slow_query_log_file               = /var/log/mysql/mysql_slow.log
tmpdir                            = /tmp
server-id                         = xx

[mysqld]
user                              = mysql
pid-file                          = /var/lib/mysql/mysqld.pid
socket                            = /var/lib/mysql/mysql.sock
port                              = 3306
basedir                           = /usr
datadir                           = /var/lib/mysql

expire_logs_days                  = 3
general_log                       = 0
general_log_file                  = /var/log/mysql/mysql_general.log
log-error                         = /var/log/mysql/mysql_error.log
log-bin                           = /var/lib/mysql/mysql_bin
slow_query_log                    = 1
slow_query_log_file               = /var/log/mysql/mysql_slow.log
tmpdir                            = /tmp
server-id                         = xx

binlog_format                     = ROW

# added binlog_row_image = MINIMAL to assist with the rbr write fail - to process large amount of rows
binlog_row_image                  = MINIMAL

default_storage_engine            = InnoDB
enforce_storage_engine            = InnoDB
back_log                          = 128
key_buffer_size                   = 512M
join_buffer_size                  = 8M
long_query_time                   = 2
# log-queries-not-using-indexes
max_allowed_packet                = 64M
max_connections                   = 360
max_heap_table_size               = 32M

net_read_timeout                  = 30
net_write_timeout                 = 30
query_cache_limit                 = 2M
query_cache_size                  = 128M
sort_buffer_size                  = 8M
table_open_cache                  = 512
thread_cache_size                 = 128
thread_stack                      = 256K
wait_timeout                      = 28800
explicit_defaults_for_timestamp

# innodb_force_recovery           = 3
innodb_buffer_pool_size           = 8G
innodb_buffer_pool_instances      = 2

innodb_file_per_table
innodb_flush_log_at_trx_commit    = 1
innodb_lock_wait_timeout          = 120
innodb_log_buffer_size            = 8M
innodb_log_file_size              = 256M
innodb_log_files_in_group         = 3

innodb_max_dirty_pages_pct        = 90
innodb_open_files                 = 1024
innodb_status_file
innodb_thread_concurrency         = 32

# innodb_locks_unsafe_for_binlog  = 1
innodb_autoinc_lock_mode          = 2

# wsrep_cluster_address           = gcomm://
wsrep_cluster_address             = gcomm://IP1,IP2,IP3
wsrep_cluster_name                = QCLUSTER
wsrep_debug                       = ON
wsrep_node_address                = xxx
wsrep_node_incoming_address       = xxx
wsrep_node_name                   = QCLUST02
wsrep_on                          = ON
wsrep_provider                    = /usr/lib64/libgalera_smm.so
wsrep_replicate_myisam            = 1
wsrep_slave_threads               = 1
wsrep_sst_method                  = rsync
wsrep_sst_auth                    = root:password

# convert locking sessions into transactions
wsrep_convert_LOCK_to_trx=0