radius 10-30/00:00:10 ERROR [rdsLstnr-p-7-t-1121] DefaultServerSetup - Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

                169248 Query    INSERT INTO inet_session_1 (id, parentId, splittedId, connectionId, sessionStart, sessionStop, lastActive, sessionTime, sessionCost, deviceState, status) VALUES (4699605,4699109,4693668,3735936,'2015-10-30 00:00:00',null,'2015-10-30 00:00:
00',0,0,0,1)

accounting 10-30/00:00:18 ERROR [accwrkr-2-p-14-t-10] SessionFlushingManager - Cannot find session for update with id=4699605, connectionId=3735936, sessionStart=2015-10-30 00:00:00.0 in DB!

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

                195954 Query    INSERT INTO inet_session_1_seq (id) VALUES (NULL)
                195954 Query    INSERT INTO inet_session_1 (id, parentId, splittedId, connectionId, sessionStart, sessionStop, lastActive, sessionTime, sessionCost, deviceState, status) VALUES (4917412,4916693,4901704,3897832,'2015-11-10 00:00:00',null,'2015-11-10 00:00:00',0,0,0,1)
                195954 Query    UPDATE inet_connection_1 SET type=2 WHERE id=3897832
                195954 Query    INSERT INTO inet_session_detail_1 (sessionId, day, hour, trafficTypeId, amount) VALUES (4917412,0,0,0,79272)
                195954 Query    INSERT INTO inet_session_detail_1 (sessionId, day, hour, trafficTypeId, amount) VALUES (4917412,0,0,3,4529380)
                195954 Query    INSERT INTO inet_session_detail_1 (sessionId, day, hour, trafficTypeId, amount) VALUES (4917412,0,0,4,5042308)
                195954 Query    UPDATE inet_session_1 SET status=3, sessionStop='2015-11-09 23:59:59' WHERE id=4901707 AND status!=3
                195954 Query    SELECT 1
                195954 Query    rollback

show variables like "%timeout%";
show variables like "%buffer%";
show variables like "%innodb_flush_log_at_trx_commit%";
show variables like "%concurr%";

mysql> show variables like "%timeout%";
+----------------------------+----------+
| Variable_name              | Value    |
+----------------------------+----------+
| connect_timeout            | 10       |
| delayed_insert_timeout     | 300      |
| innodb_lock_wait_timeout   | 120      |
| innodb_rollback_on_timeout | OFF      |
| interactive_timeout        | 28800    |
| lock_wait_timeout          | 31536000 |
| net_read_timeout           | 60       |
| net_write_timeout          | 60       |
| slave_net_timeout          | 3600     |
| wait_timeout               | 28800    |
+----------------------------+----------+
10 rows in set (0.00 sec)

mysql> show variables like "%buffer%";
+------------------------------+------------+
| Variable_name                | Value      |
+------------------------------+------------+
| bulk_insert_buffer_size      | 8388608    |
| innodb_buffer_pool_instances | 1          |
| innodb_buffer_pool_size      | 2147483648 |
| innodb_change_buffering      | all        |
| innodb_log_buffer_size       | 8388608    |
| join_buffer_size             | 131072     |
| key_buffer_size              | 8388608    |
| myisam_sort_buffer_size      | 8388608    |
| net_buffer_length            | 16384      |
| preload_buffer_size          | 32768      |
| read_buffer_size             | 131072     |
| read_rnd_buffer_size         | 262144     |
| sort_buffer_size             | 2097152    |
| sql_buffer_result            | OFF        |
+------------------------------+------------+
14 rows in set (0.00 sec)
mysql> show variables like "%innodb_flush_log_at_trx_commit%";
+--------------------------------+-------+
| Variable_name                  | Value |
+--------------------------------+-------+
| innodb_flush_log_at_trx_commit | 2     |
+--------------------------------+-------+
1 row in set (0.00 sec)

mysql> show variables like "%concurr%";
+----------------------------+-------+
| Variable_name              | Value |
+----------------------------+-------+
| concurrent_insert          | AUTO  |
| innodb_commit_concurrency  | 0     |
| innodb_concurrency_tickets | 500   |
| innodb_thread_concurrency  | 2     |
| thread_concurrency         | 48    |
+----------------------------+-------+
5 rows in set (0.00 sec)