Change Buffer Configuring the Change Buffer Maximum Size Monitoring the Change Buffer The  innodb_change_buffer_max_size  variable permits configuring the maximum size of the change buffer as a percentage of the total size of the buffer pool. By default, innodb_change_buffer_max_size  is set to 25. The maximum setting is 50. Consider increasing  innodb_change_buffer_max_size  on a MySQL server with heavy insert, update, and delete activity, where change buffer merging does not keep pace with new change buffer entries, causing the change buffer to reach its maximum size limit. Consider decreasing  innodb_change_buffer_max_size  on a MySQL server with static data used for reporting, or if the change buffer consumes too much of the memory space shared with the buffer pool, causing pages to age out of the buffer pool sooner than desired. Test different settings with a representative workload to determine an optimal configuration. The innodb_change_buffer_max_size  variable is dynamic, which permits modifying the setting without restarting the server. The following options are available for change buffer monitoring: mysql>  SHOW ENGINE INNODB STATUS\G Change buffer status information is located under the  INSERT BUFFER AND ADAPTIVE HASH INDEX heading and appears similar to the following: For more information, see Section 15.17.3, “InnoDB Standard Monitor and Lock Monitor Output” . mysql>  SELECT NAME, COMMENT FROM INFORMATION_SCHEMA.INNODB_METRICS WHERE NAME LIKE ’%ibuf%’\G For  INNODB_METRICS  table usage information, see Section 15.15.6, “InnoDB INFORMATION_SCHEMA Metrics Table” . 3014 •The  INFORMATION_SCHEMA.INNODB_BUFFER_PAGE  table provides metadata about each page in the buffer pool, including change buffer index and change buffer bitmap pages. Change buffer pages are identified by  PAGE_TYPE .  IBUF_INDEX  is the page type for change buffer index pages, and IBUF_BITMAP  is the page type for change buffer bitmap pages. •The  INFORMATION_SCHEMA.INNODB_METRICS  table provides most of the data points found in InnoDB  Standard Monitor output plus other data points. To view change buffer metrics and a description of each, issue the following query: • InnoDB  Standard Monitor output includes change buffer status information. To view monitor data, issue the  SHOW ENGINE INNODB STATUS  statement. ------------------------------------- INSERT BUFFER AND ADAPTIVE HASH INDEX ------------------------------------- Ibuf: size 1, free list len 0, seg size 2, 0 merges merged operations:  insert 0, delete mark 0, delete 0 discarded operations:  insert 0, delete mark 0, delete 0 Hash table size 4425293, used cells 32, node heap has 1 buffer(s) 13577.57 hash searches/s, 202.47 non-hash searches/s