InnoDB System Variables The replication thread delay in milliseconds on a replica server if  innodb_thread_concurrency  is reached. InnoDB  rolls back only the last statement on a transaction timeout by default. If  --innodb-rollback- on-timeout  is specified, a transaction timeout causes  InnoDB  to abort and roll back the entire transaction. For more information, see Section 15.21.4, “InnoDB Error Handling” . innodb_rollback_segments  defines the number of rollback segments allocated to each undo tablespace and the global temporary tablespace for transactions that generate undo records. The number of transactions that each rollback segment supports depends on the  InnoDB  page size and the number of undo logs assigned to each transaction. For more information, see Section 15.6.6, “Undo Logs” . For related information, see Section 15.3, “InnoDB Multi-Versioning” . For information about undo tablespaces, see Section 15.6.3.4, “Undo Tablespaces” . 3279 • innodb_saved_page_number_debug • innodb_rollback_segments • innodb_rollback_on_timeout Command-Line Format --innodb-rollback-on-timeout[={OFF| ON}] System Variable innodb_rollback_on_timeout Scope Global Dynamic No SET_VAR  Hint Applies No Type Boolean Default Value OFF Command-Line Format --innodb-rollback-segments=# System Variable innodb_rollback_segments Scope Global Dynamic Yes SET_VAR  Hint Applies No Type Integer Default Value 128 Minimum Value 1 Maximum Value 128 Command-Line Format --innodb-saved-page-number-debug=# System Variable innodb_saved_page_number_debug Scope Global Dynamic Yes