InnoDB System Variables InnoDB  tries to flush data from the buffer pool so that the percentage of dirty pages does not exceed this value. The  innodb_max_dirty_pages_pct  setting establishes a target for flushing activity. It does not affect the rate of flushing. For information about managing the rate of flushing, see Section 15.8.3.5, “Configuring Buffer Pool Flushing” . For related information, see Section 15.8.3.5, “Configuring Buffer Pool Flushing” . For general I/O tuning advice, see Section 8.5.8, “Optimizing InnoDB Disk I/O” . Defines a low water mark representing the percentage of dirty pages at which preflushing is enabled to control the dirty page ratio. A value of 0 disables the pre-flushing behavior entirely. The configured value should always be lower than the  innodb_max_dirty_pages_pct  value. For more information, see Section 15.8.3.5, “Configuring Buffer Pool Flushing” . Defines the desired maximum purge lag. If this value is exceeded, a delay is imposed on  INSERT , UPDATE , and  DELETE  operations to allow time for purge to catch up. The default value is 0, which means there is no maximum purge lag and no delay. For more information, see Section 15.8.9, “Purge Configuration” . 3264 • innodb_max_dirty_pages_pct_lwm Maximum Value 99.99 Command-Line Format --innodb-max-dirty-pages-pct-lwm=# System Variable innodb_max_dirty_pages_pct_lwm Scope Global Dynamic Yes SET_VAR  Hint Applies No Type Numeric Default Value 10 Minimum Value 0 Maximum Value 99.99 Command-Line Format --innodb-max-purge-lag=# System Variable innodb_max_purge_lag Scope Global Dynamic Yes SET_VAR  Hint Applies No Type Integer Default Value 0 Minimum Value 0 Maximum Value 4294967295 • innodb_max_purge_lag