Idle session timeout

When the idle period of the current session exceeds the specified threshold, the system will proactively close the current session. This topic describes the idle session timeout error and the troubleshooting procedure.

Error: ERROR-02013

Error message

ERROR-02013: Lost connection to MySQL server during query

Examples

After the current session remains idle for a period longer than the specified threshold, if you execute an SQL statement to query data in the t1 table, this error will be returned.

obclient> SELECT * FROM t1;
ERROR-02013: Lost connection to MySQL server during query

Troubleshooting procedure

Method 1

Reconnect to the Oracle database.

1. Reconnect the SYS user.

   [admin@k08j13249.eu95sqa /home/admin]
   $obclient -h172.10.10.10 -P1000 -usys@Oracle  -p  -A
   Enter password:
   Welcome to the OceanBase monitor.  Commands end with ; or \g.
   Your OceanBase connection id is 3221635806
   Server version: 5.7.25 OceanBase 3.2.3.0 (r20220511132422-590d9fea1ec221fa4ed446e512bd797b35dfae8f) (Built May 11 2022 13:38:24)
   
   Copyright (c) 2000, 2018, OceanBase Corporation Ab and others.
   
   Oracle is a registered trademark of Oracle Corporation and/or its
   affiliates. Other names may be trademarks of their respective
   owners.
   
   Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
   

2. Query data in the t1 table again.

   obclient> SELECT * FROM t1;
   +----+------+-------+------------------------------+
   | ID | NAME | VALUE | GMT_CREATE                   |
   +----+------+-------+------------------------------+
   |  1 | CN   |  NULL | 12-MAY-22 11.29.49.782106 AM |
   |  2 | UK   |  NULL | 12-MAY-22 11.29.49.782106 AM |
   |  3 | US   |  NULL | 12-MAY-22 11.29.49.782106 AM |
   +----+------+-------+------------------------------+
   3 rows in set
   

Method 2

Modify session timeout parameters.

1. Query the wait_timeout variable in the variables view.

   obclient> SHOW variables WHERE VARIABLE_NAME = 'wait_timeout';
   +---------------+-------+
   | VARIABLE_NAME | VALUE |
   +---------------+-------+
   | wait_timeout  | 10    |
   +---------------+-------+
   1 row in set
   
   

2. Set the 'wait_timeout 'parameter to '28800'.

 > **Note**
 >
 >This variable specifies the time in seconds that the server waits for an interactive idle connection to become active before closing it.

 ```sql
 obclient> SET wait_timeout = 28800;
 Query OK, 0 rows affected

3. Set the interactive_timeout variable to 28800.

   Note

   This variable specifies the time in seconds that the server waits for a non-interactive idle connection to become active before closing it.

   obclient> SET interactive_timeout = 28800;
   Query OK, 0 rows affected
   

4. Query data in the t1 table again.

   obclient> SELECT * FROM t1;
   +----+------+-------+------------------------------+
   | ID | NAME | VALUE | GMT_CREATE                   |
   +----+------+-------+------------------------------+
   |  1 | CN   |  NULL | 12-MAY-22 11.29.49.782106 AM |
   |  2 | UK   |  NULL | 12-MAY-22 11.29.49.782106 AM |
   |  3 | US   |  NULL | 12-MAY-22 11.29.49.782106 AM |
   +----+------+-------+------------------------------+
   3 rows in set