MySQL -- flush

mysql> SHOW VARIABLES LIKE '%innodb_io_capacity%';
+------------------------+-------+
| Variable_name| Value |
+------------------------+-------+
| innodb_io_capacity| 2000|
| innodb_io_capacity_max | 4000|
+------------------------+-------+

$ fio -filename=fio.txt -direct=1 -iodepth 1 -thread -rw=randrw -ioengine=psync -bs=16k -size=2048M -numjobs=10 -runtime=10 -group_reporting -name=mytest
...
Jobs: 10 (f=10): [m(10)][90.9%][r=155MiB/s,w=155MiB/s][r=9907,w=9896 IOPS][eta 00m:01s]
mytest: (groupid=0, jobs=10): err= 0: pid=4867: Thu Jan 31 11:26:20 2019
read: IOPS=11.2k, BW=175MiB/s (184MB/s)(1754MiB/10002msec)
...
bw (KiB/s): min=14285, max=24256, per=10.01%, avg=17978.35, stdev=2020.97, samples=190
iops: min=892, max= 1516, avg=1123.32, stdev=126.33, samples=190
write: IOPS=11.2k, BW=176MiB/s (184MB/s)(1756MiB/10002msec)
...
bw (KiB/s): min=14211, max=24480, per=10.01%, avg=17990.18, stdev=2278.29, samples=190
iops: min=888, max= 1530, avg=1124.08, stdev=142.44, samples=190

Run status group 0 (all jobs):
READ: bw=175MiB/s (184MB/s), 175MiB/s-175MiB/s (184MB/s-184MB/s), io=1754MiB (1839MB), run=10002-10002msec
WRITE: bw=176MiB/s (184MB/s), 176MiB/s-176MiB/s (184MB/s-184MB/s), io=1756MiB (1841MB), run=10002-10002msec

mysql> SHOW VARIABLES LIKE '%innodb_max_dirty_pages_pct%';
+--------------------------------+-------+
| Variable_name| Value |
+--------------------------------+-------+
| innodb_max_dirty_pages_pct| 75|
| innodb_max_dirty_pages_pct_lwm | 0|
+--------------------------------+-------+

F1(M){
if M>=innodb_max_dirty_pages_pct then
return 100;
return M/innodb_max_dirty_pages_pct * 100;
}

mysql> SHOW GLOBAL STATUS LIKE '%Innodb_buffer_pool_pages_%';
+----------------------------------+------------+
| Variable_name| Value|
+----------------------------------+------------+
| Innodb_buffer_pool_pages_data| 633395|
| Innodb_buffer_pool_pages_dirty| 99|
| Innodb_buffer_pool_pages_flushed | 1286891803 |
| Innodb_buffer_pool_pages_free| 8191|
| Innodb_buffer_pool_pages_misc| 13774|
| Innodb_buffer_pool_pages_total| 655360|
+----------------------------------+------------+

# 1. Innodb_buffer_pool_pages_data
#The number of pages in the InnoDB buffer pool containing data. The number includes both dirty and clean pages.
# 2. Innodb_buffer_pool_pages_dirty
#The current number of dirty pages in the InnoDB buffer pool.
# 3. Innodb_buffer_pool_pages_flushed
#The number of requests to flush pages from the InnoDB buffer pool.
# 4. Innodb_buffer_pool_pages_free
#The number of free pages in the InnoDB buffer pool.
# 5. Innodb_buffer_pool_pages_misc
#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.
#Innodb_buffer_pool_pages_misc = Innodb_buffer_pool_pages_total − Innodb_buffer_pool_pages_free − Innodb_buffer_pool_pages_data.
#13774 = 655360 - 8191 - 633395
# 6. Innodb_buffer_pool_pages_total
#The total size of the InnoDB buffer pool.

# Innodb_buffer_pool_pages_dirty/Innodb_buffer_pool_pages_total = 0.015%

mysql> SHOW VARIABLES LIKE '%innodb_flush_neighbors%';
+------------------------+-------+
| Variable_name| Value |
+------------------------+-------+
| innodb_flush_neighbors | 0|
+------------------------+-------+