The number of pages in the InnoDB  buffer pool that are busy because they have been allocated for administrative overhead, such as row locks or the adaptive hash index. This value can also be calculated as Innodb_buffer_pool_pages_total − Innodb_buffer_pool_pages_free − Innodb_buffer_pool_pages_data . When using compressed tables, Innodb_buffer_pool_pages_misc  may report an out-of-bounds value (Bug #59550). 

• Innodb_buffer_pool_pages_total 

The total size of the InnoDB  buffer pool, in pages. When using compressed tables, the reported Innodb_buffer_pool_pages_data  value may be larger than Innodb_buffer_pool_pages_total  (Bug #59550) 

• Innodb_buffer_pool_read_ahead 

The number of pages read into the InnoDB  buffer pool by the read-ahead background thread. 

• Innodb_buffer_pool_read_ahead_evicted 

The number of pages read into the InnoDB  buffer pool by the read-ahead background thread that were subsequently evicted without having been accessed by queries. 

• Innodb_buffer_pool_read_ahead_rnd 

The number of “random”  read-aheads initiated by InnoDB . This happens when a query scans a large portion of a table but in random order. 

• Innodb_buffer_pool_read_requests 

The number of logical read requests. 

• Innodb_buffer_pool_reads 

The number of logical reads that InnoDB  could not satisfy from the buffer pool, and had to read directly from disk. 

• Innodb_buffer_pool_resize_status 

The status of an operation to resize the InnoDB  buffer pool dynamically, triggered by setting the innodb_buffer_pool_size  parameter dynamically. The innodb_buffer_pool_size  parameter is dynamic, which allows you to resize the buffer pool without restarting the server. See Configuring InnoDB Buffer Pool Size Online for related information. 

• Innodb_buffer_pool_wait_free 

Normally, writes to the InnoDB  buffer pool happen in the background. When InnoDB  needs to read or create a page and no clean pages are available, InnoDB  flushes some dirty pages first and waits for that operation to finish. This counter counts instances of these waits. If innodb_buffer_pool_size  has been set properly, this value should be small. 

• Innodb_buffer_pool_write_requests 

The number of writes done to the InnoDB  buffer pool. 

• Innodb_data_fsyncs 

The number of fsync()  operations so far. The frequency of fsync()  calls is influenced by the setting of the innodb_flush_method  configuration option. 

