InnoDB Buffer Pool Configuration To reduce the warmup period after restarting the server,  InnoDB  saves a percentage of the most recently used pages for each buffer pool at server shutdown and restores these pages at server startup. The percentage of recently used pages that is stored is defined by the  innodb_buffer_pool_dump_pct configuration option. After restarting a busy server, there is typically a warmup period with steadily increasing throughput, as disk pages that were in the buffer pool are brought back into memory (as the same data is queried, updated, and so on). The ability to restore the buffer pool at startup shortens the warmup period by reloading disk pages that were in the buffer pool before the restart rather than waiting for DML operations to access corresponding rows. Also, I/O requests can be performed in large batches, making the overall I/ O faster. Page loading happens in the background, and does not delay database startup. In addition to saving the buffer pool state at shutdown and restoring it at startup, you can save and restore the buffer pool state at any time, while the server is running. For example, you can save the state of the buffer pool after reaching a stable throughput under a steady workload. You could also restore the previous buffer pool state after running reports or maintenance jobs that bring data pages into the buffer pool that are only requited for those operations, or after running some other non-typical workload. Even though a buffer pool can be many gigabytes in size, the buffer pool data that  InnoDB  saves to disk is tiny by comparison. Only tablespace IDs and page IDs necessary to locate the appropriate pages are saved to disk. This information is derived from the  INNODB_BUFFER_PAGE_LRU INFORMATION_SCHEMA table. By default, tablespace ID and page ID data is saved in a file named  ib_buffer_pool , which is saved to the  InnoDB  data directory. The file name and location can be modified using the innodb_buffer_pool_filename  configuration parameter. Because data is cached in and aged out of the buffer pool as it is with regular database operations, there is no problem if the disk pages are recently updated, or if a DML operation involves data that has not yet been loaded. The loading mechanism skips requested pages that no longer exist. The underlying mechanism involves a background thread that is dispatched to perform the dump and load operations. Disk pages from compressed tables are loaded into the buffer pool in their compressed form. Pages are uncompressed as usual when page contents are accessed during DML operations. Because uncompressing pages is a CPU-intensive process, it is more efficient for concurrency to perform the operation in a connection thread rather than in the single thread that performs the buffer pool restore operation. Operations related to saving and restoring the buffer pool state are described in the following topics: Before dumping pages from the buffer pool, you can configure the percentage of most-recently-used buffer pool pages that you want to dump by setting the  innodb_buffer_pool_dump_pct  option. If you plan to dump buffer pool pages while the server is running, you can configure the option dynamically: Configuring the Dump Percentage for Buffer Pool Pages 3120 •Monitoring Buffer Pool Load Progress Using Performance Schema •Aborting a Buffer Pool Load Operation •Displaying Buffer Pool Load Progress •Displaying Buffer Pool Dump Progress •Saving and Restoring the Buffer Pool State Online •Saving the Buffer Pool State at Shutdown and Restoring it at Startup •Configuring the Dump Percentage for Buffer Pool Pages