InnoDB System Variables innodb_io_capacity_max  variable defines a maximum number of IOPS performed by  InnoDB background tasks in such situations. For information about configuring the  innodb_io_capacity_max  variable, see Section 15.8.7, “Configuring InnoDB I/O Capacity” . • innodb_limit_optimistic_insert_debug Command-Line Format --innodb-limit-optimistic-insert- debug=# System Variable innodb_limit_optimistic_insert_debug Scope Global Dynamic Yes SET_VAR  Hint Applies No Type Integer Default Value 0 Minimum Value 0 Maximum Value 2**32-1 Limits the number of records per B-tree page. A default value of 0 means that no limit is imposed. This option is only available if debugging support is compiled in using the  WITH_DEBUG CMake  option. • innodb_lock_wait_timeout Command-Line Format --innodb-lock-wait-timeout=# System Variable innodb_lock_wait_timeout Scope Global, Session Dynamic Yes SET_VAR  Hint Applies No Type Integer Default Value 50 Minimum Value 1 Maximum Value 1073741824 The length of time in seconds an  InnoDB  transaction waits for a row lock before giving up. The default value is 50 seconds. A transaction that tries to access a row that is locked by another  InnoDB transaction waits at most this many seconds for write access to the row before issuing the following error: When a lock wait timeout occurs, the current statement is rolled back (not the entire transaction). To have the entire transaction roll back, start the server with the  --innodb-rollback-on-timeout option. See also Section 15.21.4, “InnoDB Error Handling” . You might decrease this value for highly interactive applications or OLTP systems, to display user feedback quickly or put the update into a queue for processing later. You might increase this value for 3256 ERROR 1205 (HY000): Lock wait timeout exceeded; try restarting transaction