ERROR 2006 (HY000): MySQL server has gone away No connection. Trying to reconnect

Hi,
I am not sure whether this questions belongs to Cluster side or just mysql server side.

I have set wait_timeout and interactive_timeout to 3600 ( 1 hr) but it looks like I see error message even much before 1 hr
So what is causing this behavior ?

mysql> select * from test ;
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect…
Connection id: 114677


mysql> show global variables like '%timeout';
+-----------------------------+----------+
| Variable_name | Value |
+-----------------------------+----------+
| connect_timeout | 10 |
| delayed_insert_timeout | 300 |
| have_statement_timeout | YES |
| innodb_flush_log_at_timeout | 1 |
| innodb_lock_wait_timeout | 50 |
| innodb_rollback_on_timeout | OFF |
| interactive_timeout | 3600 |
| lock_wait_timeout | 31536000 |
| net_read_timeout | 30 |
| net_write_timeout | 60 |
| rpl_stop_slave_timeout | 31536000 |
| slave_net_timeout | 3600 |
| thread_pool_idle_timeout | 3600 |
| wait_timeout | 3600 |
+-----------------------------+----------+
14 rows in set (0.03 sec)