Timeout for big Select-Statements with Maria-DB

[RKTWorker]

Switching from MySQL 5.7 to Maria-DB 10.6 with Java-Connector-Lib 3.1.0 (https://mariadb.com/kb/en/about-mariadb-connector-j/) we had some problems with our select statements.

Big select statements led to a DB timeout.

Proposed Solutions

• Although the select statement is valid, it is possible to shrink it a bit.
• Another solution could be to increase the DB timeout

Acceptance Criterion

Select statements of plausibly-designed and plausibly-used Storables can be executed in Maria-DB without adjusting default timeouts. For complex Storables, it shall work with adjusted timeouts.

[csc-gip]

https://mariadb.com/kb/en/server-system-variables/#sql_big_selects https://dev.mysql.com/doc/refman/5.7/en/server-system-variables.html#sysvar_sql_big_selects

[csc-gip]

mysql[(none)] > show global variables like  "%timeout%";
+---------------------------------------+----------+
| Variable_name                         | Value    |
+---------------------------------------+----------+
| connect_timeout                       | 10       |
| deadlock_timeout_long                 | 50000000 |
| deadlock_timeout_short                | 10000    |
| delayed_insert_timeout                | 300      |
| idle_readonly_transaction_timeout     | 0        |
| idle_transaction_timeout              | 0        |
| idle_write_transaction_timeout        | 0        |
| innodb_flush_log_at_timeout           | 1        |
| innodb_lock_wait_timeout              | 50       |
| innodb_rollback_on_timeout            | OFF      |
| interactive_timeout                   | 28800    |
| lock_wait_timeout                     | 86400    |
| net_read_timeout                      | 30       |
| net_write_timeout                     | 60       |
| rpl_semi_sync_master_timeout          | 10000    |
| rpl_semi_sync_slave_kill_conn_timeout | 5        |
| slave_net_timeout                     | 60       |
| thread_pool_idle_timeout              | 60       |
| wait_timeout                          | 360000   |
+---------------------------------------+----------+
19 rows in set (0,001 sec)

mysql[(none)] > show variables like  "%timeout%";
+---------------------------------------+----------+
| Variable_name                         | Value    |
+---------------------------------------+----------+
| connect_timeout                       | 10       |
| deadlock_timeout_long                 | 50000000 |
| deadlock_timeout_short                | 10000    |
| delayed_insert_timeout                | 300      |
| idle_readonly_transaction_timeout     | 0        |
| idle_transaction_timeout              | 0        |
| idle_write_transaction_timeout        | 0        |
| innodb_flush_log_at_timeout           | 1        |
| innodb_lock_wait_timeout              | 50       |
| innodb_rollback_on_timeout            | OFF      |
| interactive_timeout                   | 28800    |
| lock_wait_timeout                     | 86400    |
| net_read_timeout                      | 30       |
| net_write_timeout                     | 60       |
| rpl_semi_sync_master_timeout          | 10000    |
| rpl_semi_sync_slave_kill_conn_timeout | 5        |
| slave_net_timeout                     | 60       |
| thread_pool_idle_timeout              | 60       |
| wait_timeout                          | 28800    |
+---------------------------------------+----------+
19 rows in set (0,001 sec)

mysql[(none)] >

[csc-gip]

mysql5.7

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         | 28800    |
| lock_wait_timeout           | 31536000 |
| net_read_timeout            | 30       |
| net_write_timeout           | 60       |
| rpl_stop_slave_timeout      | 31536000 |
| slave_net_timeout           | 60       |
| wait_timeout                | 360000   |
+-----------------------------+----------+
13 rows in set (0.00 sec)

mysql> show 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         | 28800    |
| lock_wait_timeout           | 31536000 |
| net_read_timeout            | 30       |
| net_write_timeout           | 60       |
| rpl_stop_slave_timeout      | 31536000 |
| slave_net_timeout           | 60       |
| wait_timeout                | 28800    |
+-----------------------------+----------+
13 rows in set (0.01 sec)