Mariadb version: 5.5.56
connector version : mariadb-connector-c-2.2.3

I have a client-server based architecture setup where maria DB is used in back-end server for data storage .We are using TLS version TLSv1.2 for MySQL communication.
While running the set up with increased data load an error was reported - After few minutes of high volume data load communication , mariadb started showing intermittent occurrence of "MySQL Error no 5" which maps to EE_OUTOFMEMORY (Out of memory). NOTE that this error EE_OUTOFMEMORY appeared intermittently for 3-4 minutes and after that MySQL error 7d3 started occurring continuously when trying to communicate with MySQL.
Error 7d3 is a MySQL client error which maps to CR_CONN_HOST_ERROR (Can't connect to MySQL server).

We had to restart DB for restoring proper communication .

We need your help to know

• The possible reasons for EE_OUTOFMEMORY (Out of memory) error from DB? The system has enough RAM available at that time, although we don't have the process memory state at that time.
• How we can diagnose the reason why this EE_OUTOFMEMORY (Out of memory) occurred??
• How to prevent this error EE_OUTOFMEMORY (Out of memory) from occurring?? If there are MySQL parameters that needs to be tuned to prevent this??

For information - The tuning parameters used by db in our case are :

SSL_CIPHER=TLSv1.2 --user=mysql --log-error=* --max_connections=100000 --wait_timeout=600 --interactive_timeout=600 --max_connect_errors=1000 --max_allowed_packet=16M --sort_buffer_size=256M --bulk_insert_buffer_size=128M
--tmp_table_size=32M --max_heap_table_size=128M --key_buffer_size=128M --table_open_cache=1000 --read_buffer_size=128M --read_rnd_buffer_size=64M --query_cache_limit=64M --query_cache_size=512M
--slow_query_log=1 --long_query_time=10 --slow_query_log_file=$SLOW_QUERY_LOG

Let us know if any additional details are required.